Arsenal won at Anfield for the first time in 14 years after Kai Havertz's strike sealed a gritty 1-0 victory - but Liverpool were denied what looked to be a clear penalty.
The result opens up a three-point gap on Manchester City at the top of the Premier League - and means Mikel Arteta's side are nine clear of Liverpool.
In a battle of attrition, the only discernible difference was at the top end. Liverpool's various waves of pressure almost always led to an effort on David Raya's goal - 17 in total - but none actually forced the goalkeeper into a save.
Florian Wirtz hit the crossbar with a free-kick and Alexis Mac Allister - who was caught in a nonsense confrontation with Noni Madueke late on - ballooned a header over the bar unmarked, but Andoni Iraola's side failed to land a single shot on target at home for the first time on record.
"It's been a defensive masterclass from Arsenal," said Gary Neville. Liverpool have scored just four league goals in five Anfield outings this term.
The blunted hosts might have had an opportunity from the penalty spot to change that, but Jurrien Timber's less-than-subtle tug on Alexander Isak's shirt in the first half was not spotted by the officials, prompting Jamie Carragher to tell VAR to "do its job".
For the remainder of the game, Arsenal did theirs. Havertz's decider meant he became the division's top-scoring German with 46 goals in total, overtaking former Man City midfielder Ilkay Gundogan, and made sure his side collected another statement win in defence of their title.
Your Site' Gary Neville at Anfield:
"It was a defensive masterclass. Iraola will be upset, he'll feel like his team have given everything, but the champions have turned up in a season of uncertainty, sabotaged by the Man City saga.
"They can only do the job they continue to do and that puts them right in the driving seat. What a tough place this is to play football and they've come and conquered it."
16: GOAL! Havertz steers home at the back post from a cutting Declan Rice cross.
21: NO PENALTY! Bradley Barcola delivers a teasing cross that Isak glances wide of the post, but he was held back by Timber. Officials did not spot the foul.
29: NO PENALTY! Cody Gakpo tangles with Christos Tzolis, who was the wrong side of the Liverpool forward, but again the officials are unmoved.
36: WIDE! Isak flashes a low strike wide of the near post on the swivel.
39: WOODWORK! Wirtz curls a wicked free kick against the upright.
43: MISS! Milos Kerkez's shapes a perfect cross for Mac Allister to meet on the run but he powers a header horribly over from eight yards.
73: SAVE! Alisson brilliantly denies Tzolis' low strike to keep Liverpool alive in the game.
79: CLASH! Mac Allister was caught in a head-to-head confrontation with Madueke late on, falling to the ground and holding his face. VAR reviewed the incident and deemed no violent conduct, instead booking Mac Allister.
Liverpool boss Andoni Iraola:
"The Alex Isak one is a clear penalty. You hold the shirt; we can all see that he holds the shirt. The ball just goes one centimetre in front of Alex."
On whether the player needed to go down: "The fact that you are even asking me that he should have gone to the floor, that's the thing. If he goes to the floor, they call the penalty. They call the penalty 100 per cent."
On whether he will instruct his players to go down in the future: "Yes, definitely. Alex is honest, he plays for the goal. It's a clear, clear pull."
Arsenal boss Mikel Arteta:
"It feels better as a manager [to win at Anfield], because it's been such a long time. We really needed it. We're extremely proud, especially because of the conditions we arrive in the game after defeat to Fleetwood. We had to pick ourselves up.
"This is the mission, which we hadn't completed for 14 years. We knew we needed to nail absolutely everything and navigate through periods where we suffer. They create chaos moments. It was very impressive and I'm very happy."
On changing the Anfield record: "I had the feeling, now is the moment, we had to dig deep and have an element of luck at times. We had quality in key moments and we've done it."
