Substitute Yoane Wissa struck a dramatic 94th-minute winner to give Brentford a 2-1 victory over West Ham United at the London Stadium on Sunday as the promoted side continued their superb start to life in the Premier League.

The game seemed to be heading for a draw before Wissa scored through the crowd from eight yards out after Lukasz Fabianski had punched away a towering header from Pontus Jansson.

"It was very good... I know I needed one chance to score. It's a good feeling, good atmosphere, very happy for the fans... it was now or never because we had too many chances to score in the first half," said Wissa, who signed from Ligue 1 club Lorient in the summer.

Brentford flew out of the blocks and almost netted twice in the opening exchanges before Bryan Mbeumo made the pressure count in the 20th minute when he slotted home after Fabianski could only parry a low drive from Sergi Canos.

"We deserved to be up in the first half. We defended well in the box," said Brentford manager Thomas Frank.

West Ham were sharper after the break and nearly equalised through former Brentford winger Said Benrahma, whose curling free kick was smartly tipped over by David Raya.

The home side were rewarded in the 80th minute when Jarrod Bowen lashed home a fine half-volley following Aaron Cresswell's corner.

"I don't think we played well in the second half, after the storm settled they scored the goal... if you look at the game, it was a 1-1 game, we were better in the first half, West Ham were better in the second half," Frank added.

Brentford moved up to seventh in the table with 12 points. West Ham are a point behind in ninth. (Reuters)