A few minutes before half-time in a contest that largely swung one way but briefly veered the other, Brighton threatened what was then a rare foray into Arsenal territory.

For a short moment the visitors seemed certain to muster their first shot of an afternoon that had hitherto been miserable. But, no sooner had Maxim De Cuyper received the ball on the counterattack, the Belgian was flattened by a crunching Declan Rice tackle that killed any threat. De Cuyper slumped; Rice, towering over him, roared – arguably this season’s standout Premier League midfielder making light of playing right-back for the first time in his Arsenal career.

If Arsenal are to win the Premier League this season, a ceaseless succession of injuries would render it a feat of staggering proportions. Rice the right-back; Mikel Merino the striker; Christian Nørgaard the centre-back – all have been seen at points this season. Even Saturday’s teamsheet had to be altered when the left-back Riccardo Calafiori dropped out after feeling a niggle in the warmup. There were an abundance of available excuses if a Brighton comeback had come to pass.

That it did not owed much to a resilience required numerous times this season: almost half of Arsenal’s matches in all competitions have been drawn or decided by a single goal.

The hosts’ failure to kill off the game after Martin Ødegaard’s opener and a Georginio Rutter own goal could have cost them. Diego Gómez unexpectedly pulled a goal back amid a period of Brighton threat in which David Raya also pulled off a wonder save to deny Yankuba Minteh. Asked whether it was sustainable for Arsenal to keep coming so close to capitulating at the back end of home games, Mikel Arteta answered simply: “Yes.”

Supporters would rather not have to endure such frequently raised pulses, but the wins keep coming and, for successive weekends, Arsenal followed an earlier Manchester City victory by climbing back to the top of the table.

“Very happy with the performance,” Arteta said. “Individually and collectively so dominant. We were a big threat, so very pleased with that, but the margin should have been much bigger. It should never be 2-1, but that’s the Premier League.

“We should have scored the third one and then it would have been different. We haven’t, so we have to suffer a little bit more.”

The Arsenal manager suggested the frequency of injuries was serving as a unifying force and insisted his side can continue to weather them: “At the moment we survived six months, so let’s see – hopefully things will get better.”

Notwithstanding a 20-minute anxiety-inducing period of Brighton threat in the second half, it was a triumph of some ease. With Ødegaard pulling the strings, and Leandro Trossard and Bukayo Saka terrorising their hapless Brighton handlers, the winning margin should have been considerably greater. By half-time Arsenal had registered 15 shots to Brighton’s zero.

Only one of those was converted after the hosts seized on a botched Brighton short goal-kick and capitalised with calm assurance. Saka fed Ødegaard, whose drilled finish into the bottom corner was his first goal of an injury-troubled campaign.

The lead was doubled via a familiar route soon after half-time. A customary whipped Rice corner caused Rutter to flick the ball into his own net for Arsenal to benefit from a fourth own goal in their past three home games.

By that stage things might have been worse for Brighton, who were perhaps fortunate not to have Bart Verbruggen sent off for flattening Viktor Gyökeres after charging out of his box. The proximity of the touchline meant it was not deemed a goalscoring opportunity, with the goalkeeper instead shown a yellow card.

Having offered no attacking threat, the visitors unexpectedly pulled a goal back out of nothing just after the hour when Yasin Ayari’s low drive hit the post and Gómez hammered in the rebound. An uncomfortable tension rose around the Emirates Stadium, but Brighton could not find an equaliser.

“In the first half we didn’t play a good game,” said Fabian Hürzeler, whose Brighton side have not won any of their past 11 games in the month of December. “The second half completely the opposite; a lot of courage. In the end it’s a disappointing result.”