Andre Gray warned Manchester City to write Watford off at their peril after Javi Gracia's men dug deep to reach the FA Cup final with a stunning comeback against Wolves.

A day after a humdrum victory for Pep Guardiola's quadruple-chasing City side against Brighton, Wembley bore witness to an enthralling semi-final encounter.

Matt Doherty and Raul Jimenez goals looked to have sealed Wolves the win on Sunday, only for Watford substitute Gerard Deulofeu to reduce the deficit in superb fashion before Troy Deeney's stoppage-time penalty took the game into extra time.

Wolves floundered in the additional 30 minutes and Gray sent Deulofeu through to wrap up a remarkable 3-2 win, securing Watford's place in the FA Cup final for the first time since their only previous appearance in 1984.

"Crazy," striker Gray told Press Association Sport after the match. "That's why we love the game.

"I think 65 minutes, we're 2-0 down and you're thinking 'Jesus, how has this happened?' Two set-pieces, which we're usually good at defending.

"But I think we just had to grind it out.

"We never give up and I think that showed, and we just had to play rough and just do the simple things and play dirty.

"And it managed to pay off in the end.

"The way we did it as well: the extra-time, the drama of it, fighting until the end, holding on, waiting for the ref to blow the whistle.

"It all makes it that little more sweeter."

The fact Gray was released by hometown club Wolves as a boy provides further satisfaction, so does his rise from non-league football to the FA Cup final.

Watford are priced by some bookmakers at 13-2 to win the May 18 showpiece, but Gracia's men proved on Sunday they have the skill, spirit and strength to hurt City at Wembley.

"Yeah, look, anything can happen," Gray said with a laugh. "It's the final now. It's just about the day.

"Everyone would have wrote us off today after 65 minutes but look what happened.

"It's going to be a special day and, like I said, anything can happen."

Watford's second FA Cup final appearance is sure to be a special occasion and caps a fine season in which their current 46-point haul is already their best return in the Premier League era, and best in the top fight since 1986-87.

Asked if Gracia has built a special group, Gray said: "Yeah, look, I think it's so hard to come back from 2-0 down, it's so difficult, especially against a team like Wolves.

"We just showed that spirit we've got. I think if you've seen the scenes in the changing room after, it's incredible.

"Like, for instance, Gerry (Deulofeu) didn't play (from the start) today. He's obviously frustrated and stuff, but the team ethic even if he's doing it for himself, he's come on to try and prove a point and he's gone and scored two and won us the game."

Jimenez may have been announced as man of the match in the dying embers of regulation time, but there is no doubt that super sub Deulofeu was the star man after a stunning brace that assures his place in Watford folklore.

"Troy is so effective at that, just getting flick-ons and winning headers and stuff and it worked perfect," Gray said of the build-up to Deulofeu's winner.

"It's obviously dropped to me, me and Gerry had a one-two. As soon as I put him in, and he took the touch there was only one outcome.

"His ability is incredible.

"But the manager has got tough decisions to make. Whether it's me, whether it's him, whether it's Troy, Maxi [Roberto Pereyra], it's part of the game.

"It's just how you react to it and, credit to him today, he's reacted in the right way."