Craig Gardner’s extra-time stunner sent Birmingham to Wembley after their Carling Cup comeback sunk West Ham at St Andrew’s.

Gardner scored four minutes after the re-start of the semi-final clash, after goals from Lee Bowyer and Roger Johnson cancelled out Carlton Cole’s opener for a 3-1 home win.

Blues now face Arsenal – their first major final in 10 years – but the result was marred by crowd trouble outside the ground as rival fans clashed near the away entrance, forcing police to make 14 arrests before the game.

On the pitch, though, a comeback looked unlikely before the half-time introduction of Nikola Zigic changed the tie.

West Ham, 2-1 ahead from the first leg, dominated for long spells in the first-half and took the lead after half an hour.

Cole received Wayne Bridge’s quick throw with little impending danger, but he quickly brushed off Barry Ferguson’s challenge and curled into the far corner from 25-yards.

It was no more than the Hammers deserved, after a fine opening which had already seen Zavon Hines twice test goalkeeper Ben Foster.

In contrast, Blues struggled to get going and failed to seriously threaten goalkeeper Robert Green in the opening 45 minutes, aside from Matt Derbyshire’s angled drive.

That changed after the break, when Zigic replaced Derbyshire and immediately unsettled the Hammers.

First the Serbia international nodded down for Gardner to strike the post from 20-yards as Birmingham rallied.

Then they equalised on 59 minutes when Zigic caused chaos in the Hammers’ backline and the loose ball fell to Bowyer to lash into the top corner against his former club.

Ferguson’s drive then had Green scrambling and the goalkeeper tipped Jerome’s header over before the hosts levelled the tie 11 minutes from time.

Following Green’s save from Jerome, Larsson tossed in a corner and Johnson got the better of Matthew Upson to power a header in.

Jerome should have fired Blues ahead two minutes later but was denied by Green’s legs when put through.

Gardner almost won it with one of the last kicks of normal time after latching onto a loose ball but Green turned his effort onto the post.

But the midfielder wasn’t to be denied in extra time when his low drive beat Green to the delight of the home fans.

Parker ballooned over soon after and Foster saved from Cole, but Birmingham held on to spark pandemonium.