Leo Ulloa scored on his Albion debut today – but his side were denied an FA Cup replay by Theo Walcott’s late deflected winner.

Walcott came off the bench to volley the 85th-minute clincher as Arsenal won 3-2 in a pulsating fourth round tie at The Amex.

The Seagulls twice came from behind to cancel out goals by the outstanding Olivier Giroud.

Ashley Barnes headed home a David Lopez corner on 33 minutes in response to Giroud’s glorious 16th-minute finish into the top corner.

Giroud ran on to Abou Diaby’s pass to thrash a volley past Casper Ankergren on 57 minutes.

But Ulloa replied six minutes later with a diving header right in front of the North Stand from Barnes’ terrific cross.

Walcott and Jack Wilshere made an impact coming off the bench but the clincher had a bit of luck about it.

Ankergren, who made a handful of good saves, could only punch a corner away as far as Walcott and his volley deflected in off Adam El-Abd.