Danny Welbeck scored a late equaliser as Albion came from behind to draw with Sheffield United at the Amex.
The visitors, who are still without a win this season, had played for 55 minutes with ten men after John Lundstram was sent off for a foul on John Veltman but they went in front through substitute Jayden Bogle early in the second half.
Albion bossed possession but the Blades were well organised and looked to be on their way to their first win of the season when Welbeck pounced from close range with a volley into the roof of the net four minutes from time.
Graham Potter made three changes with Tariq Lamptey missing through injury while Steven Alzate and Danny Welbeck dropped to the bench. In came Joel Veltman, Neal Maupay and Aaron Connolly. Following the recent rule change, Albion named nine subs with Jayson Molumby and Andi Zeqiri on the bench.
Albion began on the front foot with Trossard and Solly March prominent although it wasn't until the 22nd minute before United keeper Aaron Ramsdale was tested when he saved an angled effort from Connolly, who had been played in by a lovely pass from Adam Lallana.
They then had two great chances in the space of six minutes. Yves Bissouma released Trossard down the right and the Belgian picked out Maupay, but his flick goalwards was blocked by Chris Basham and Ramsdale gratefully pounced on the loose ball.
The French forward was involved again on 31 minutes when Adam Webster met Trossard's corner with a header that Maupay helped on but Ethan Ampadu got the block in this time.
Rob Sanchez had been a spectator on his Amex debut but the Spanish keeper made an outstanding save when David McGoldrick's free kick from the edge of the D was turned around the post.
United had just began to get a bit of control when they went down to ten men in the 38th minute. Referee Peter Bankes initially showed Lundstram a yellow for a late challenge on Veltman, but after the video assistant referee Michael Oliver intervened he changed his decision and sent Lundstram off.
Potter made an attacking change at the break, bringing on Alireza Jahanbakhsh for Veltman and with only Burke on his own up front, United set out their stall to stay compact and make it as hard as possible to be broken down. Jahanbakhsh was soon involved, setting up Trossard who fired wide.
Albion predictably dominated possession but they were nearly punished on when Burke broke from halfway and laid the ball into the path of Enda Stevens, who drilled his effort from the edge of the box inches wide.
The home fans howled for a penalty when Ramsdale smothered the ball at Connolly's feet but it got worse on 63 minutes. The tireless McGoldrick picked out substitute Jayden Bogle and his strike from the edge of the box deflected off Webster and flew past a helpless Sanchez.
Webster nearly made a decisive intervention at the other end when his shot was palmed over by Ramsdale, but it had turned into a frustrating afternoon for Albion.
The arrival of Zeqiri, for his Albion debut, and Danny Welbeck provided different attacking threats but with 15 minutes to go the Blades were looking comfortable.
Lewis Dunk got on the end of March's corner but headed straight at Ramsdale but with eight minutes left Connolly seemed to certain to equalise after the visitors' keeper missed Jahanbakhsh's cross, but the striker headed over from inside the six yard box.
Burke nearly got a second on the counter, firing wide from George Baldock's cross before Albion finally broke through. Trossard's ball into the box bounced off Basham as he challenged with Webster and Welbeck chested it down in a packed six-yard box and lashed it into the roof of the net.
There was drama deep into stoppage time when Jahanbakhsh headed against the post and buried his head in his hands. It summed up a frustrating afternoon but there was also relief that Albion at least got some reward for their efforts.
Sanchez; Veltman, Dunk, Webster, White (Zeqiri 72) March, Bissouma, Lallana, Trossard, Connolly, Maupay (sub: Welbeck 67).
Subs not used: Steele, Burn, Jahanbakhsh, Propper, Alzate, Molumby.
Referee: Peter Bankes