Trossard's goal breaks Goodison park curse
Trossard, a first-half substitute for the injured Gabriel Martinelli, struck his winner in style, firing a first-time finish in off the post from Bukayo Saka's pass following a smartly-worked corner.
It came after a controversially-disallowed Martinelli strike in the first half, when Eddie Nketiah was found to be fractionally offside by VAR earlier in the passage of play, despite the ball only reaching him via a heavy deflection off Everton striker Beto.
The disallowed goal proved a pivotal moment in the first half. Arsenal had started positively but the incident, which saw Martinelli pull up with a hamstring injury after scoring, caused them to lose momentum and allowed Everton to gain a foothold.
Arsenal continued to probe, however, with Trossard's first Premier League goal of the season eventually clinching a long-awaited Goodison victory which moves the Gunners up to fourth while continuing Everton's winless start to the campaign.
Debutant David Raya, picked in goal instead of Aaron Ramsdale in a boldly-chosen Arsenal team which also included Fabio Vieira ahead of Kai Havertz, had been a spectator during the early stages but had to dive to his right to save an Idrissa Gueye effort from range.
When explaining his reasoning for dropping Ramsdale for the first time, Arteta said he treated the goalkeeping position as any other - even to the point where he has considered changing 'keeper midway through games in the past.