Arsene Wenger hailed Alexis Sanchez as "an animal" after he scored an extra-time winner in Arsenal's FA Cup semi-final victory over Manchester City and insisted the forward will stay at the Emirates Stadium next season.

Sanchez struck in the 101st minute at Wembley on Sunday, sealing the Gunners' comeback after Nacho Monreal had equalised following Sergio Aguero's opener.

The Chile international is facing an uncertain future with Arsenal given his contract is due to expire in 2018 and talks over a renewal are on hold until the end of the season.

But in praising Sanchez's performance against City, Wenger vowed he would at the very least see out his contract and hopefully extend his deal.

"Alexis Sanchez was like the team," Wenger said to BBC Sport after the match.

"He had problems to start and became stronger and stronger. He is an animal, always ready to kill the opponent. He will never give up. 

"He will be here next year because he has a contract and hopefully we will manage to extend him."

Wenger also discussed his three-man defence, which he deployed for a second straight game, and made a point of highlighting Mesut Ozil for praise.

The Arsenal boss added: "Maybe we have found a period where we needed a bit more security and [the system] helps with that. 

"The players look like they were comfortable the positions they are playing in. 

"They did [deliver] - not only those who scored goals but many people questioned Ozil and he has shown that sometimes he can fight as well. 

"Overall it was a great team performance, not only technically but mentally. We became stronger and in the end deserved to win the game.

"The team performance was there. When the players give their best and are completely focused you always stand up for them.

"We were close to scoring and on the break they are very good. We lost the ball and conceded the goal but we showed the right response."