Arsenal ground out a 1-0 win over Brighton to capitalise on Manchester City's slip-up against Nottingham Forest and move seven points clear at the top of the Premier League.
As their title rivals were held to a 2-2 draw at the Etihad Stadium, Bukayo Saka's deflected, ninth-minute strike proved decisive for the Gunners in a scrappy, fractious encounter on the south coast.
Brighton boss Fabian Hurzeler said "only one side tried to play football" after the game as he accused Arsenal of time-wasting tactics involving David Raya, who went to ground on three occasions.
"What a surprise," said Mikel Arteta in response to Hurzeler's comments.
Saka's goal, which squirmed past Bart Verbruggen after taking a touch off Carlos Baleba, came from one of only two shots on target by Arsenal, who laboured in possession but excelled defensively.
Brighton dominated most of the game, registering 60 per cent of the possession, but Arsenal, led by defenders Gabriel and Piero Hincapie, and without the injured William Saliba, could not be breached.
Brighton's best chance came after only two minutes, when David Raya sent a pass straight to Baleba, whose attempted chip had to be cleared off the line by Gabriel.
The hosts pinned Arsenal in their own half for long periods, but only mustered a further two shots on target, with Raya saving well from Georginio Rutter as the home fans became increasingly frustrated by the perceived time-wasting from the visitors.
Arsenal had a chance to put the game beyond Brighton when substitute Kai Havertz had a diagonal effort saved by Verbruggen, but their slender lead meant they had to survive a nervy finale.
The final whistle, and news of Manchester City's draw with Forest, prompted wild celebrations from the travelling fans as Arsenal opened up a seven-point gap, albeit having played a game more.
Brighton boss Fabian Hurzeler slammed Arsenal's approach in an explosive press conference, saying: "We could have even created more chances, but overall, like you said, in the end we lost, so we are all disappointed regarding the performance.
"I love the effort from my boys, I loved how they played football. I think there was only one team who tried to play football today and therefore I'm proud of how they did it.
"I ask one question, did you see in the Premier League game a goalkeeper going down three times? No? So I think we shouldn't waste too many words about that tonight.
"We should focus on us, we should focus on our performance. We can't control these kind of things.
"I think therefore the Premier League has to find the rule and it's not my business. I made my point before the game and I stick to it."
Arsenal manager Mikel Arteta offered only short responses to his opposite number's criticism, saying: "What a surprise."
Asked if he could expand on that comment, he said: "You just go back to the previous games and you'll find a lot of comments like this always.
"I love my players. That's the highlight. I love my players, we love our players and I love the way we compete."
Asked if he cared about the comments of other managers, he said: "Care? Yeah. Depends." Depends on the manager? "Yeah, and the comments. And the purpose of that.
"Obviously, when you are in the position that we are in, they want to take that away from you. That's normal, that's sport.
"We need to take that with normality and we need to confront it in the right way."
Hurzeler's comments will dominate the fallout from the game. He had made a point of raising the time-wasting issue in his pre-match press conference so it was no surprise to hear him return to the subject after a fractious evening which ended in defeat for his side.
His frustration was justified, at least to some extent. Having taken an early lead, Arsenal were clearly eager to disrupt the flow of the game, provoking the ire of the home fans as well as the manager, who spent much of the night remonstrating with the fourth official.
This was an ugly game. Its stop-start nature certainly suited the visitors better than Brighton. But, against an Arsenal side clearly out of sorts, Hurzeler might also look at his own side's shortcomings. They had more than enough possession to hurt Arsenal but couldn't.
Their 11 shots were worth just 0.8 expected goals, according to Opta, and for all their dominance of the ball and of territory, it was telling that Raya didn't have a save to make after the 63rd minute, when Mats Wieffer headed directly at him.
Hurzeler has succeeded in shaping the narrative in the wake of this game. But his complaints should be of little concern to the Arsenal fans who sang 'we're going to win the league' in the away end. This ugly victory was one to savour for them.
