Upson, skippering the side in the absence of Lucas Neill, received a hostile reception on his first return to St Andrews since his $15million January move to Upton Park.

But Mark Noble ensured Alan Curbishley's side regained their pride after the home reversal by Manchester City with a 68th minute spot-kick after Blues 'keeper Colin Doyle was adjudged to have brought down Craig Bellamy.

It leaves Birmingham still searching for their first win of the campaign - and in desperate need of a midfield play-maker before the transfer window closes in two weeks.

The Hammers, who gave a debut to £6 million capture Kieron Dyer, deserved their success for an improved second half performance after neither side looked threatening in the first half.

Noble impressed in the centre of the park - the only survivor in that department from the side which faced Manchester City - and the margin of victory would have been greater had Bobby Zamora showed more clinical finishing.

Liam Ridgewell again impressed at the heart of the increasingly over-worked City back four and when they ventured forward too often the final ball was lacking in creativity.

Hayden Mullins became the first player to be yellow carded after five minutes for holding back Birmingham midfielder Sebastian Larsson.

Dyer appealed in vain for a penalty after being challenged by Stephen Kelly following a typical surge into the home area.

Garry O'Connor, who scored his first goal for City in the mid-week draw with Sunderland, tried his luck from 25 yards out but screwed his shot across the face of the goal.

Blues major share-holder Carson Yeung looked on from the directors box - and saw the woodwork deny West Ham from taking a 25th minute lead.

Rahdi Jaidi handled some 35 yards from the Birmingham goal and Mark Noble's fierce skidding drive beat the dive of Colin Doyle but thumped against the post.

Blues retaliated and Mikael Forssell would have been disappointed to have sliced his shot well wide when he bore down on the Hammers goal.

Doyle looked uncertain in the air on more than one occasion but reacted well to cling onto a fierce drive across the box from Spector which took a wicked deflection off Jaidi.

Parnaby became the first Birmingham player to be yellow-carded after 34 minutes for fouling George McCartney.

Spector was also booked for showing dissent towards a linesman after disputing a free-kick awarded against him for a challenge on Larsson.

Birmingham's best attempt of the opening half came in injury-time when Robert Green parried Rahdi Jaidi's shot after Forssell's initial attempt had been blocked following a Larsson free-kick.

West Ham looked more dangerous after the break and a mazy run by Noble took him to the by-line before squaring the ball back into the path of Craig Bellamy.

His first-time shot was blocked by Ridgewell and the ball eventually squirmed out of play.

Doyle did well to block an effort from Etherington and Kelly put in a great challenge to halt Zamora in the box.

It now all West Ham and Zamora twice should have done better in the space of three minutes.

The ex Brighton player should have at least hit the target after controlling a deep Ferdinand cross but lofted over the bar. Then Zamora volleyed over from close range after another good run by Etherington.

The Hammers finally went ahead after 68 minutes when Doyle was adjudged to have brought down Bellamy on the right side of the box. Up stepped Noble to make no mistake from the penalty spot.

City substitute McSheffrey forced Green to tip a skidding 30 yard free-kick around the post.

Bellamy could have opened his Hammers account but his volley was only half-hit and saved by Doyle who also denied Dyer after he raced completely clear.