As Manchester City and Liverpool prepare to go head to head at the Etihad Stadium, live on Sky Sports on Thursday, we pick out 10 key moments in the Premier League title race so far.
Spurs storm Old Trafford
Tottenham underlined their title credentials by inflicting the biggest home defeat of Jose Mourinho's career in the first big clash of the season on August 28.
Lucas Moura scored twice to consign United to their worst start to a Premier League season since 2014.
Having finished a distant second last season, United had hoped to mount a more sustained assault on Manchester City's crown, but by the end of the summer, it already looked like they were out of the race.
Mourinho walked out of his post-match press conference, having asked journalists for a greater show of respect, adding: "Just to finish, do you know what the result was? Three-nil.
"Do you know what this means?" he asked the room, holding up three fingers. "Three-nil but it also means three Premier Leagues, and I won more alone than the other 19 managers together.
"Three for me and two for them," he added, referencing Pep Guardiola and Manuel Pellegrini's Premier League titles with City.
Tottenham's bad September
That impressive result at United contributed to Tottenham's best start to a top-flight season since 2009, but it masked uncertainty off the pitch.
Spurs became the first side in Premier League history to fail to make a single summer signing, while frustration grew among supporters over delays to the new stadium.
Back on the field, a defeat to early pace-setters Watford at Vicarage Road before the first international break only served to underline why many believed Spurs lacked the squad depth to challenge for the title.
"Everyone can be a big personality in the dressing room when you are winning, but a punch on the nose like this will find out if you are a proper team," said Graeme Souness after Watford's second-half fightback.
"Can you brush the criticism away and deal with the disappointment? Whether it's the biggest game of the season or one of the less-fancied teams you do what you have to do to get back on track."
Tottenham were unable to do that, however, with their subsequent 2-1 loss to Liverpool at Wembley instead showing how far Jurgen Klopp's side had come since they were beaten 4-1 there 11 months earlier.
Sturridge saves Liverpool at Chelsea
Liverpool's win over Spurs meant that, for the first time since 1990, they had won their opening five league games to a season. But they were not alone, with Chelsea enjoying a perfect start under Maurizio Sarri.
Arsenal were one of the sides beaten by the Blues, while Man City had been held at Wolves. Chelsea's draw at West Ham meant they went into their home clash with Liverpool on September 29 two points behind Klopp's side.
Eden Hazard's strike looked to have won it for Chelsea, and the Belgian wasted a glorious chance to put the game to bed as Alisson denied him when through on goal.
The miss proved costly as Daniel Sturridge emerged from the substitutes' bench and scored three minutes later to earn an invaluable point.
Sarri admitted afterwards that he felt Liverpool and now leaders Manchester City were "one step ahead" of his side, but also that he was "starting to think" he could bridge the gap in one season.
Mahrez fluffs his lines
In what is proving a more costly miss with each passing week, City had the chance to open up a three-point lead on Liverpool when they were awarded an 85th-minute penalty as the two teams came face-to-face at Anfield on October 7.
Virgil van Dijk was penalised for a foul on Leroy Sane inside the box, but after consultation with team-mate Gabriel Jesus over who should be the taker, Riyad Mahrez's penalty cleared the crossbar and the points were shared.
It stretched City's wait for a win at Anfield to 18 games, while Liverpool's unbeaten start remained intact. At the time, it still felt like a good point for City, and Fernandinho's man-of-the-match performance underlined his importance to the side.
But losing a game so late in the day could have represented a huge psychological blow to Klopp's side.
City halt Spurs recovery
After the defeat to Liverpool, Tottenham recovered to win four consecutive Premier League games and move back into the Champions League places ahead of their Monday Night Football meeting with City.
Liverpool had beaten Cardiff 4-1 at Anfield two days earlier to move top of the table on 26 points - matching their equivalent tally in the 2008/09 campaign, when they finished second.
So the pressure was on City ahead of the one of their most difficult games of the season, but Tottenham rarely troubled Ederson as Guardiola's men recorded a seventh clean sheet in their opening 10 games.
On a Wembley surface scarred by an NFL encounter 24 hours earlier, City returned to the summit on goal difference courtesy of Mahrez's sixth-minute winner.
Lacazette makes something out of nothing
Two defeats in their opening two games under new manager Unai Emery had illustrated the task the Spaniard faced in turning Arsenal back into title contenders, but they went into their home game with Liverpool on November 3 on the back of a 12-match unbeaten run.
Arsenal had been expected to win many of those games, but this was the litmus test for Emery. Rescuing a point courtesy of Alexandre Lacazette's 82nd-minute equaliser increased belief that the Gunners' resurgence was not a false dawn - and it also handed the initiative back to City.
The following day, Southampton were trounced 6-1 at the Etihad Stadium as the defending Premier League champions took advantage of Liverpool dropping points to move two clear at the top.
Son runs Chelsea ragged
Tottenham recovered from the 1-0 defeat to City by winning their next four in all competitions ahead of facing Chelsea at Wembley on November 24.
Sarri's side were still unbeaten in the league, but further draws with United and Everton had left them four points off the pace.
With leaders City thumping West Ham 4-0 at the London Stadium and Liverpool being made to work hard for their 3-0 success at Watford, the pressure was on Chelsea to keep up with the pace.
Tottenham led courtesy of Dele Alli's headed opener but Chelsea were then denied a penalty when Eden Hazard appeared to be caught by Juan Foyth inside the box.
Ultimately, Spurs went on to outplay them, with Son Heung-Min's brilliant solo goal bringing a ruthless end to Chelsea's unbeaten record.
Origi comes in from the cold
With City beating Bournemouth in routine fashion on the Saturday to open up a five-point lead, the pressure was on Liverpool to keep on their coat-tails when they hosted their Merseyside rivals Everton on December 2.
But they were thankful for a brilliant reaction save from Alisson to deny Andre Gomes during an open first half in which Xherdan Shaqiri and Sadio Mane both went close at the other end.
A more defensive second-half display from Marco Silva's side looked to have earned Everton a point, but substitute Divock Origi pounced on a mistake by Jordan Pickford in the 96th minute to clinch a vital three points for the Reds.
It was a bizarre winner, after Virgil van Dijk's sliced shot had bounced back into play off the crossbar, with Origi on hand to nod in his first Liverpool goal since May 2017.
Injuries mount for City
Despite a fresh setback for Kevin de Bruyne in November, City had looked omnipotent until they travelled to Chelsea on December 8, where a 2-0 defeat, coupled with Liverpool's 4-0 win at Bournemouth meant a change at the top.
But a first league defeat of the season also came with the additional blow of a hamstring injury to David Silva, and it's not just in the creative department where City have suffered.
The loss of Fernandinho with a thigh strain, heading into the festive period, has underlined just why Guardiola was keen to sign another defensive midfielder in the summer.
City's title bid was further hit by defeats to Crystal Palace and Leicester either side of Christmas in Fernandinho's absence, allowing Liverpool to open up a considerable lead at the top.
Liverpool hit five past Arsenal
Liverpool faced a real test of their title credentials with Arsenal's visit to Anfield on Saturday, but hours after second-placed Tottenham had slumped to a 3-1 loss to Wolves, Klopp's men opened up a nine-point lead with a thumping 5-1 win over Unai Emery's side.
It was their most emphatic state of intent yet. Liverpool fell behind to Ainsley Maitland-Niles' opening goal, but they responded in stunning style, smashing four goals before half-time and adding their fifth in the second half as Roberto Firmino completed a hat-trick.
Manchester City cut Liverpool's nine-point lead to seven with their 3-1 win over Southampton the following day, but the manner in which the Reds dismantled Arsenal was a message to their rivals which sets up Thursday's showdown at the Etihad Stadium perfectly.