BIRMINGHAM, England - Aston Villa came from behind to defeat West Ham United 2-1 in the FA Cup third round on Friday after a controversial goal from Amadou Onana and a strike from Morgan Rogers denied Graham Potter a victory in his first game as the visitors' manager.

A day after Potter was unveiled as Julen Lopetegui's replacement, Lucas Paqueta got West Ham on the scoresheet in the ninth minute when Crysensio Summerville played a square ball across the box that the Brazilian slotted into the net.

But Villa grew into the game and Onana equalized in the 71st from a disputed corner, with Lukasz Fabianski saving Ian Maatsen's shot before the midfielder hammered home.

West Ham argued the corner should not have been given and television replays showed they had a case, with Onana firing the ball over the goal line with no visiting players near it.

"We're surprised it was a corner. But the referee has given it. There's nothing we can do now," Potter told the BBC.

Rogers popped up with the winner for the hosts five minutes later, slotting Ollie Watkins' square pass into the corner.

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"It shows a lot of belief in the changing room that we know we can come back against anyone," Rogers told ITV.

Villa were knocked out by Chelsea in the fourth round last year but have now reached that stage in consecutive campaigns for the first time since 2014-15 and 2015-16.

"I am very happy because we played a very good match," said Villa boss Unai Emery. "We're getting stronger and more imposing. We finished strong. To win is very important for the confidence."

Injuries were the story of a mostly dull first half, with West Ham losing forward Niclas Fullkrug to a hamstring issue after 16 minutes before Villa's Ross Barkley limped off with an apparent ankle problem seven minutes later.

The Hammers did deservedly go in 1-0 ahead at the interval but Villa stepped it up after the break to take the lead and Jacob Ramsey was also unlucky to hit the post late on.

West Ham striker Danny Ings did have two terrific chances in added time but his first shot was blocked by Rogers and he could not sort his feet out for the second, swiping the ball high and wide while falling as Potter buried his head in his hands.

"The players have had a big week, a difficult week," said the former Chelsea boss. "We need to recover and refresh."

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In the night's other tie, League One (third-tier) Wycombe progressed with a 2-0 home win over Championship side Portsmouth with first-half goals from Brandon Hanlan and Sonny Bradley.