Brighton extended their winning run at the Amex Stadium to three matches with a 2-0 win over struggling Norwich.
The Seagulls had to wait for their first home win of the season, against Tottenham on October 5, but have now followed it up with wins over Everton and Norwich.
And Brighton sealed the three points in the 84th minute when Shane Duffy slid in to tap home a Trossard free-kick.
In contrast, Norwich have lost five of their last six, and remain second from bottom having amassed just seven points from 11 matches.
The Canaries remain without a win since their shock victory over Manchester City on September 14 and have managed to secure just one point away from Carrow Road in the Premier League this season.
Norwich had started the game well and came closest in the first half when Marco Stiepermann hit the bar, but as the game went on they struggled to build pressure and Brighton began to dominate.
Brighton looked to be on course to break the deadlock when Steven Alzate drove into the centre of the box before taking his shot, only to be denied by an outstretched leg from Tim Krul.
Midfielder Alzate had a second chance to score, with a dipped effort from the edge of the box passing just wide of the Norwich net.
The Seagulls were forced into an early change when centre-back Adam Webster was carried off on a stretcher in the 36th minute with what appeared to be an ankle problem.
With the half-time whistle approaching, the ball looped to Neal Maupay in the area, but the Seagulls’ top scorer was unable to control it, with some last-ditch defending from Norwich keeping Brighton at bay.
Dale Stephens dragged wide at the start of the second half, but it was a sign of the mounting pressure from the hosts.
And that pressure resulted in Brighton finally breaking the deadlock in the 68th minute when Trossard got an important touch from a Martin Montoya cross to turn the ball past Krul and into the net.
Moments later came Norwich’s best chance of the half but Emiliano Buendia fired into the side netting.
Brighton put the game beyond the Canaries when goalscorer Trossard turned provider with a free-kick which Duffy managed to get the final touch on for his second goal of the season.