Will this be remembered as the night Kai Havertz turned a corner?
The 21-year-old has endured a difficult first season at Chelsea following his £72m arrival from Bayer Leverkusen but he was the standout player in Monday's 2-0 win over Everton.
Havertz, pushed forward into the false nine role, produced the game's two decisive moments, his shot from Marcos Alonso's cross bouncing in off Ben Godfrey for the opener before he sprinted onto Mateo Kovacic's pass to win the penalty for Chelsea's second.
He had the ball in the net himself on another occasion, rifling home from a Callum Hudson-Odoi cross only to have the goal ruled out for a marginal handball call following a VAR review.
Those were the highlights but Thomas Tuchel will be just as encouraged by his all-round performance. Havertz was a menace throughout, dropping back into midfield to link the play at times and charging in behind the Everton defence at others.
It was a clever and confident performance from the German and Carlo Ancelotti's side struggled to get a handle on him.
"He showed up between the lines in offensive positions and used his potential to accelerate our game and to increase our touches in the box," said Tuchel afterwards. "He took the responsibility to assist and also to finish himself. This is what we want."
This was Havertz's first start since Tuchel's first game in charge. He has been unfortunate with injuries this season and a knock had ruled him out of Chelsea's last few games. But carry on like this and he will soon start to justify that £72m price-tag.
The London Stadium has been like a white elephant for West Ham fans for a long time, but imagine if their return to watching the Hammers next season included a round of Champions League games.
It sounds like pure madness; even in the days of Hurst, of Moore, of Peters, of Brooking, European Cup football was never played in east London. With the quality of sides around them, logic dictates it probably will not be next season.
Logic is not something that can be associated with the Hammers season, though. West Ham have gone from fighting for survival to fighting for continental qualification, and over the course of what is almost three quarters of a season, it has gone beyond any kind of fluke.
Declan Rice's assessment was simple. "It's a great football environment, and that shows on the pitch, how we are off the pitch." Oversimplistic? Probably not. Just because a good dressing room is easy to pinpoint does not make it easy to cultivate.
West Ham just keep on going, and now have a five-point gap to Liverpool in eighth - with seventh perhaps enough for a European spot - and a game in hand over Jurgen Klopp's side.
There are 11 cup finals left for Moyes' team. Manchester United, Arsenal and Leicester make up three of their next four games, teams who have the experience and know-how of recent success.
Those results will be so crucial in writing their own names into club folklore, because with the kind of attritional, winning football the Hammers produced to beat Leeds on Monday night and so often this season, they have a chance.
Everton travelled to Stamford Bridge riding high on the back of a three-game winning streak that had thrust the Toffees into Champions League contention.
Before his return to Stamford Bridge, the Italian spoke up the chances of the blue half of Merseyside competing with Chelsea both on the pitch and in the race for the top four, but there was no performance to back his pre-match prophecy, and instead it was his comments after Everton's timid defeat on Monday night which spoke volumes.
"We have to be honest; we are not at the same level," Ancelotti said. "We cannot play an open game against this kind of team."
It wasn't that Everton didn't show up at Stamford Bridge, far from it. For large parts they were solid and assured in defence, keeping Chelsea opportunities to a minimum.
But the quality which had seen Everton beat Liverpool, Southampton and West Brom, and propelled them into the top-four picture, was found wanting.
Thomas Tuchel's side had a number of gears that went unused as they cantered to a 2-0 victory which bolstered their own top-four challenge and offered a sobering reality check to Everton's Champions League ambitions.
Such lofty targets may just be beyond this group at this moment in time but qualifying for Europe by any means would still represent progression for Everton. Ancelotti and his players can ill-afford many more performances like this if that is to be realised,
It took Jurgen Klopp five years to build his empire at Liverpool, but in the space of just six home games last season's powerhouse of the Premier League has crumbled right in front of his eyes.
Unbeaten in 68 home league games before Burnley cracked the Anfield enigma code in early February, their once fortress has been assailed a further five times, with Fulham the latest to extend an unwanted club-record run of home defeats, which now reads six games.
- Liverpool 0-1 Fulham - Match report and free highlights
- Carra: Liverpool mentality midgets
- Get Sky Sports | Get a Sky Sports Pass
- Live football on Sky Sports
The fear factor that once had teams beaten before they stepped foot on the hallowed Anfield turf is no more, instead a remarkable turning of the tables has seen Liverpool gripped with anxiety in the place they call home.
The very legacy Klopp built by delivering Champions League and Premier League crowns is unravelling. Seven pre-match changes failed to produce a response to the defeat by Chelsea and showed Liverpool's problems run deeper than the first XI, and no solution appears in sight.
Klopp swatted away suggestions from those - namely Fulham midfielder Harrison Reed - who called his players' desire into question, but with their title defence long gone and their top-four challenge in tatters, Liverpool are running out of opportunities to prove their manager right.
Salvation at the end of this most-arduous of Liverpool campaigns could still come in the Champions League. With almost irreputable damage done, it would seem that is the only way they can rescue their reputation.
When Bruno Fernandes cracked in his second-minute penalty he raced towards the photographers with his hands over his ears. A response to recent criticism of his performances against top opposition? Perhaps.
While Manchester United had to sustain plenty of Manchester City pressure later in that half, their impressive performance after the interval, which was capped by Luke Shaw's strike to make it 2-0, was also a good response to the questions they've had around their intent in big games this season.
- Man City 0-2 Man Utd - Match report and free highlights
- Premier League table | Premier League top scorers
- Premier League fixtures | Premier League results
Of course, this isn't the first time United have upset the odds at against City at the Etihad. Since the start of last season, they've won three in a row at their rivals across all competitions. But this could be an important marker for the future.
With 10 to play next season, United cannot afford to be 11 points off the pace again. A serious title challenge will be demanded of them. And they will need their best performers on fire in the key moments and to show a ruthlessness to take wins off the other leading sides to achieve that.
For now, this is a moment to celebrate and enjoy the bragging rights over their neighbours. But there is hard work to come on and off the pitch if Untied are to close the gap on this still formidable Man City side.
Momentum had taken over at Manchester City. Opponents were facing Pep Guardiola's side already beaten before the first whistle. The defence had treated it as an affront to concede even a shot on target, The Daily Telegraph's James Ducker pointed out on Super Sunday Matchday.
That remains the mindset and the extent of the momentum City have got. But the 28-game unbeaten run had to end somewhere.
Until now, this has been a collective effort; players have been taken out, others have come in, and the rhythm of the machine has remained unperturbed.
The consistency and confidence over the past four months had been frightening, but defeat in the Manchester derby will certainly irk Guardiola.
Ole Gunnar Solskjaer enjoys his trips to the Etihad, winning for a third time in a row in all competitions.
It continues an unwanted trend for City, who have been revolutionised on and off the pitch since moving away from Maine Road, but they have still lost more league Manchester derbies than they have won on home turf since 2003.
Guardiola was right in his post-match assessment; his side have played worse and won, but United were comfortable. City's flow has been formidable, but Solskjaer's side formed the stronger collective unit to at least slow down the procession to a third title in four years.
No team has failed to win the Premier League from Manchester City's position of strength: for teams who have played 28 games and were at least 11 points ahead, there has never been such a seismic collapse.
Guardiola won't allow himself to veer away from focusing on the next game, Southampton back at the Etihad on Sky Sports on Wednesday.
Key to City's success has been their refusal of the mind to drift. Their perspective will shift soon enough to whether they can achieve that elusive maiden Champions League title, but the title is not yet boxed off.
Scott Parker has often been a solitary champion of his squad's resilience this season, even when results may have suggested otherwise.
Fulham's survival bid has been laden with impressive performances, but the lack of points to show for those performances has been used as a stick to beat Parker's side and justification to write off their survival hopes.
With the clock ticking down, and games ticking away, Fulham needed a big performance not only to prove those doubters wrong but to vindicate Parker's process and, crucially, to get points on the board. They did just that at Anfield.
Liverpool's seven pre-match alterations may have given Fulham added incentive before kick-off, but this gutsy, adventurous result was the culmination of a season of spirited performances.
Time and time again Fulham have fallen just short, but three points at Anfield has left them well in contention in the most important race of all. With just goal difference separating the Cottagers and safety, write Fulham off at your peril.
Barely eight days ago Spurs were approaching their game against Burnley with top-four hopes fading fast, and two of their biggest names getting little to no playing time.
Suddenly, they're within one win of the Champions League spots, Gareth Bale looks a world-beater again, and even Dele Alli has a smile on his face. The latter didn't play in Spurs' 4-1 victory over Crystal Palace, but there are arguably bigger games to come as Jose Mourinho's rotation skills are tested.
Tottenham hit 100 goals in all competitions this season with the win on Sunday - as Mourinho says, not bad for a "negative" team - but this seemed more about confidence than tactics.
For Bale in particular, the difference was obvious. He'd looked inhibited in his previous starts before this week, and as his former Wales manager Chris Coleman said on commentary, like every game was his "first game back". But on Sunday he was a livewire, looked more focus and simply tried more of the tricks that make him the effective player we all know he can be.
Defensively, too, Bale showed more than in any previous appearance this season. That side of the game is simply a non-negotiable for Mourinho.
Confidence has ebbed and flowed all season for Mourinho's Spurs, but this is clearly a good moment. With the Bale and Alli situations seemingly resolved for now, the platform is there for a top-four assault. As many predicted, it looks good man-management from Mourinho.
With all the negativity coming out of Newcastle this week in the wake of the Matt Ritchie fallout, many would have expected to crumble when the pressure was on at West Brom, especially without their three key attackers available. Not many clubs could legitimacy get maximum points in a game at this level without players of importance such as Allan Saint-Maximin, Miguel Almiron and Callum Wilson.
And although the Toon rarely looked like taking three points at the Baggies, they didn't half dig in for their manager and defend with great determination. West Brom sent in 29 crosses over the 90 minutes, many of them with quality from Conor Townsend and the most West Brom have produced in a game this season, but Ciaran Clark and Jamaal Lascelles didn't give the opposition a sniff.
Performances of such negativity won't be accepted nine times out of 10 by the Toon faithful but needs must at the moment for Bruce. A point was initially a good result as it kept the Baggies nine points away from Newcastle's tails. However, Fulham's win at Liverpool now leaves the Toon as favourites by the bookmakers to be that third team to be relegated
A relegation scrap awaits Bruce and his boys but they do at least look up for the fight.
Mbaye Diagne hasn't really grabbed many headlines since joining in February. On the face of it his signing has been a mistake with just one goal in eight games but that only tells half the story - he has been the nearly man for the Baggies and could've been the next Geoff Horsfield with a bit more luck.
Since signing, no player in the Premier League has a higher expected goal figure than Diagne's - in those eight games the quality of chance falling his way has accumulated 4.63 goals. That's over a goal more than any other player in the league. That doesn't include the effort he had ruled out for offside by VAR in the 1-0 defeat to Everton, too.
In total, he has missed eight big chances since joining on loan and his confidence looked low vs Newcastle, snatching at chances and losing balance at critical times when his teammates found him in space.
Conor Townsend will feel especially aggrieved with his team-mates for not taking any of the chances he put on a plate for them in the 0-0 draw. The impressive Townsend created five chances in the match, the most from open play by a West Brom player in the Premier League since April 2014. His quality shone in a largely forgettable affair that once again didn't fall Diagne's way.