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Mikel Arteta’s men arrived at Amex Stadium having dropped to third place on the table after Manchester City’s 4-2 win at Crystal Palace in the day's early kick-off.

Fit-again top scorer Saka set the Gunners on course to return to the summit by converting a debatable first-half penalty before substitute Trossard sealed victory over his former club after a tap-in from Havertz.

The north London visitors were worthy winners on the south coast and sit a point ahead of both Liverpool, which plays its game in hand at Manchester United on Monday (AEST), and City as attention switches to a UEFA Champions League quarter-final tie with Bayern Munich.

Brighton faded from a strong start and, despite being unhappy with the decision to award a spot-kick for Tariq Lamptey’s challenge on Gabriel Jesus, could have few complaints about the result.

The Seagulls’ first top-flight home loss in 13 outings dating back to August leaves them with an uphill task to secure continental football for the second successive year on the back of this season’s UEFA Europa League adventure.

England international Saka overcame a muscle injury to start and was recalled alongside Declan Rice, Jorginho and Jesus after last week's routine 2-0 win over Luton Town.

Brighton began brightly in an entertaining opening but it was Arsenal that created but squandered a string of early chances.

After Gabriel headed wastefully off target from Martin Odegaard’s free-kick, the lively Saka curled narrowly wide before teeing up Jesus to force a fine diving save out of Bart Verbruggen.

Gunners manager Arteta expressed further frustration on the touchline just two minutes later when Jesus failed to test Seagulls goalkeeper Verbruggen with an unmarked header from a Havertz cross.

For all of their neat interplay, Brighton, whose five changes included a recall for former Arsenal forward Danny Welbeck, was lacking a cutting edge.

Lamptey had been central to the Seagulls’ slick start but moments after returning to the field from treatment he gifted the Gunners a golden chance to edge ahead.

While the full-back brushed the ball with his left foot as he brought down Jesus in the 18-yard box, referee John Brooks had little hesitation in pointing to the spot, allowing Saka to confidently find the bottom left corner from 12 yards and claim his 14th league goal this term.

Unhappy home fans wasted little time in venting their displeasure at the perceived injustice of the 33rd-minute opener as the contest slipped into a temporary lull.

Julio Enciso almost enlivened Seagulls supporters with a stunning curling effort from distance, which was clawed away by David Raya, before the match officials were jeered off at the break.

Arsenal could easily have been out of sight at the interval but came back out with plenty still to do.

Jesus and Odegaard each went close to doubling the lead before the Gunners delivered the knockout blow in the 62nd minute.

Jorginho was alert to intercept Enciso’s attempted pass deep in Albion territory and, after receiving the ball back from Odegaard, his low centre from the right was slotted home by Havertz in front of the sold-out away end.

Arteta exuberantly celebrated the strike and promptly withdrew Saka and Jesus ahead of this week's quarter-final first leg at home to Bayern in the UEFA Champions League.

Roberto De Zerbi’s injury-hit hosts had little answer to the two-goal deficit and contributed to their own undoing for the Gunners’ third as Trossard, who left Albion last year, rubbed salt into the wounds four minutes from time.

Pascal Gross’s dithering allowed Havertz to release Belgium forward Trossard and he ran half the length of the pitch before dinking over Verbruggen to seal Arsenal’s 10th league win from 11 outings in 2024.