Arsenal returned to form with a convincing 2-0 victory over Newcastle, who remain winless in the Premier League this season.
With Eddie Howe in the dugout for the first time since taking over after recovering from Covid-19, Newcastle fell behind when Bukayo Saka drilled home on 56 minutes.
Saka limped off minutes later, but his replacement Gabriel Martinelli scored within 93 seconds of being on the pitch, skilfully finishing off a long pass from Takehiro Tomiyasu.
Arsenal have now won 18 of the last 19 meetings in all competitions with Newcastle.
Howe has a huge job on his hands as the Toon remain the only side still without a Premier League win this season while Mikel Arteta's team are now unbeaten in eight games at the Emirates in all competitions, winning seven of those.
- How the teams lined up | Match stats
- Saka set to undergo scan on muscular injury
- Premier League results | Table
- Get Sky Sports | Live football on Sky Sports
Arsenal: Ramsdale (8), Tomiyasu (7), Gabriel (8), White (7), Tavares (7), Partey (7), Lokonga (7), Saka (8), Smith Rowe (7), Odegaard (7), Aubameyang (5)
Subs: Martinelli (8), Lacazette (6)
Newcastle: Dubravka (7), Schar (6), Lascelles (6), Krafth (6), Ritchie (6), Shelvey (7), Willock (6), Saint-Maximin (6), Joelinton (5), Fraser (6), Wilson (6)
Subs: Almiron (6), Murphy (6), Hayden (6)
Man of the match: Gabriel
Howe's miserable start: Arsenal too strong at home...
Former Bournemouth boss Howe was in the dugout having finally tested negative after previously contracting Covid-19.
Callum Wilson failed to make the most of an early Newcastle break and was flagged offside anyway as Howe's men were happy to sit in a compact defensive formation. It was Arsenal's task to break them down and Martin Odegaard saw a well-whipped free-kick smartly saved by Martin Dubravka as Arsenal started to take control midway through the half.
- Mikel Arteta made one change from the defeat at Liverpool as Martin Odegaard came in for his first start since the draw with Crystal Palace in October.
- Eddie Howe made three changes from the draw with Brentford. Martin Dubravka made his first appearance of the season in goal as Karl Darlow lost his spot. Also, Emil Krafth and Ryan Fraser started.
Jonjo Shelvey unleashed a piledriver strike to cut the Gunners' one-way traffic, only to see Aaron Ramsdale brilliantly tip the ball onto the bar.
Pierre-Emerick Aubameyang was then responsible for one of the misses of the season.
Saka's byline cross begged to be buried but Emile Smith Rowe nodded into the middle of the goal, allowing Dubravka to parry. The rebound fell to Aubameyang but he couldn't believe it as his side-footed effort grazed the outside of the post from a yard off the line.
Newcastle reached the half-time interval by far the happier with the game goalless, but quickly saw their outlook turn bleak after the break.
Arsenal upped the intensity down the left and Nuno Tavares - who had a disappointing evening at Anfield - flicked a lovely ball around the corner for Saka to fire into the net.
No sooner had the England forward trudged off with an injury issue than his replacement doubled the home side's advantage.
After Wilson had a penalty appeal waved away by Stuart Attwell, Martinelli latched onto Tomiyasu's chipped pass into the inside-right channel, delivering a first-time finish of genuine quality.
Newcastle had no answers and remain firmly in a relegation scrap.
Man of the match: Gabriel Magalhaes
This was further evidence of Gabriel's rapid development with another impressive defensive performance. He was tasked with handling the threat of Callum Wilson and was up to the task of keeping the Newcastle striker quiet by engaging him with huge physicality. Wilson failed to have a single effort on goal in the match.
The Aaron Ramsdale, Ben White and Gabriel axis continues to shine. In nine games together they have managed six clean sheets with just eight goals conceded - four of those coming in one game at Liverpool.
What the managers said
Arsenal boss Mikel Arteta said: "In the first half we took the game where we wanted but without being a real threat and understanding how we needed to attack that [defensive] block. We lacked some composure in the final third, we could have played the final ball better, the shooting - I don't know how many times we shot without hitting the target at all.
"In the second half we changed a few things. Our rhythm, our purpose was much better and we started to generate chances. We managed to score two and obviously the game was in control."
Newcastle boss Eddie Howe said: "I thought it was a good performance, especially the start. We were good for the first half an hour. We came under pressure. The game was decided in the incident with Callum Wilson and the penalty - a tough call against us - then they scored in the aftermath.
"I don't know why Callum would go down - he was one on one, a great chance. Games swing on those moments. It feels like those big calls have gone against us.
"Great save [from Aaron Ramsdale to deny Jonjo Shelvey]. I thought it was in. The pleasing thing today is how we started and finished the game. We created chances. Ramsdale has played well. We weren't clinical but at least we were creating chances.
"The players have been very responsive. They have given everything in the two games. I can't ask more than their best."
Analysis: Super Saka stepping up
Sky Sports' Lewis Jones:
Big players make big game-changing moments when it matters most. Bukayo Saka is a big-game player.
Arsenal were in control against Newcastle but the score was still 0-0 with 50 minutes on the clock. Eddie Howe was hanging in there with too many Arsenal attacks ending in wayward off-target finishes. The home crowd expected more against a team with no wins and who concede goals for fun.
It required a mature head to make the difference. With Pierre-Emerick Aubameyang in lacklustre mood, it was Saka, who has only just turned 20, who took the game by the scruff of the neck in the style of one of the main leaders of this progressive Arsenal side. On 51 minutes, Saka twisted and turned past Matt Ritchie before firing an effort at Martin Dubravka.
That lifted the crowd and Saka continued to lead the charge, whipping a sensational cross into the six-yard box moments later that no Arsenal player had read. The momentum towards the Newcastle goal was now at its peak and Saka found the game-changing moment on 55 minutes. He started the move on the left, linking in silky fashion with Emile Smith Rowe before making a third-man run that was spotted by Nuno Tavares.
There was a sense of inevitability as Saka drew his left foot back and found the bottom corner. That is what we expect now of this impressive young man. He is Arsenal's most dangerous and important weapon. Mikel Arteta will be hoping the knock that forced him off isn't a long-term problem. Arsenal can't afford to lose him.
- Arsenal have won seven consecutive competitive games against an opponent without conceding a single goal for the first time in their history.
- Newcastle United have become the sixth different team to fail to win any of their opening 13 games to a Premier League season, with four of the previous five sides suffering relegation (Derby in 2000-01 survived).
- Newcastle have lost 33 Premier League matches against Arsenal, their highest total against a single side in the competition's history.
- Since Arteta's first home game in charge in December 2019, only three teams (Man City, Liverpool, Chelsea) have won more points at home in the Premier League than Arsenal (67).
- Howe has taken just five points from 33 available in his Premier League meetings with Arsenal (W1 D2 L8), losing all six of his visits to the Emirates to face the Gunners.
Arsenal now go to Manchester United in the Premier League on Thursday night at 8.15pm, while Newcastle host Norwich on Tuesday at 7.30pm. Free highlights from both games will be available on the Sky Sports website, App and YouTube channel.