London  - Arsenal reached the FA Cup semi-final as they came from behind Tuesday to beat Hull City 2-1.

Veteran forward Nick Barmby gave Hull a first-half lead, only for Robin van Persie to level with 17 minutes remaining.

With seven minutes to go, William Gallas headed into an empty net to give Arsenal the win, despite appearing to be offside.

Hull had controlled the early stages, but Arsenal battled back and were the dominant side in the second half.

The opener came for Hull after 13 minutes. Andy Dawson's lofted ball found Barmby, who hit the dropping ball first time. It struck the thigh of Johan Djourou, looped up over Lukasz Fabianski and just under the bar.

Fabianski made an excellent diving save to keep out a Geovanni free-kick, and from the resulting corner Barmby looked very unlucky to have a potential second goal ruled out for offside.

Kamil Zayatte headed just over, and it was only in the final 10 minutes of the half that Arsenal began to play.

It took a superb block from Sam Ricketts to deny Andrei Arshavin, and the Russian, playing with eight stitches in his right foot, then flashed a volley just wide just before the break.

Arsenal's surge continued after half-time.

Abou Diaby sent a header flashing just wide, and Van Persie had a header from another corner cleared off the line by Dawson.

The Dutch forward then had a low free-kick pushed wide by Hull goalkeeper Boaz Myhill, before hitting the bar with a header.

But the equalizer eventually arrived.

Nicklas Bendtner's shot skewed across goal to Arshavin, who showed great presence of mind to square for Van Persie to ram home.

The winner arrived 10 minutes later as Kieran Gibbs pumped a long free-kick toward the Hull box.

Myhill, who had looked shaky on crosses all night, flapped at it, which may have confused referee Mike Riley, but it was Djourou's touch that carried the ball on to Gallas, who was clearly offside as he headed it in.

Arsenal will face Chelsea in the last four, with Manchester United playing Everton in the other semi-final. dpa