Sheffield United striker Paul Devlin made a dream return to St. Andrews to send his former club Birmingham crashing to a shock defeat.

Devlin scored the opening goal in the 4th minute and then set up the second for Martin Smith as United secured only their second away league win of the season.

But the defeat for Birmingham, who saw Martin Grainger miss a first-half penalty, was a major setback to their promotion hopes as they are losing touch with the play-off pack after a run that has seen them win just one of their last six games.

Devlin stunned his former club when he nodded United ahead from close range after United striker Marcus Bent had flicked on a cross from Wayne Quinn.

Birmingham were rocked by the setback and they would have slipped even further behind had not been for the smart reactions of goalkeeper Kevin Poole.

Poole twice denied another Birmingham old boy, midfielder Jonathan Hunt, in the sixth minute.

Birmingham eventually managed to weather the storm and force their way back into the game and they should have drawn level in the 31st minute after being awarded a controversial penalty.

Referee Graham Frankland judged that Quinn had handled the ball under pressure from Dele Adebola.

Midfielder Grainger strode forward to take the spot-kick, but his shot was beaten away by the United goalkeeper Simon Tracey.

Grainger then pounced on the rebound, but his second attempt was also beaten away by Tracey who turned the ball away for a corner.

It was to prove to be a costly miss as even a half-time roasting failed to spark Birmingham into life.

They did threaten briefly when midfielder Steve Robinson was denied in the 53rd minute by Tracey.

But Birmingham's problems were perfectly summed up when Robinson, who has only just returned to action after a long-term absence with a knee injury, was forced off following a collision with Tracey.

United then ended Birmingham's hopes when Devlin whipped over a 64th-minute cross that Smith headed home for his 14th goal of the season to secure a well-deserved success.

Birmingham: Poole, Bass, Holdsworth, Johnson, Charlton (Dyson 69), Robinson (Holland 53), Hughes, O'Connor, Grainger, Adebola (Purse 82), Marcelo.

Subs Not Used: Gill, Bennett.

Booked: O'Connor.

Sheff Utd: Tracey, Kozluk, Murphy, Sandford, Quinn, Devlin (Hamilton 89), Derry, Hunt, Brown, Bent (Gybreches 90), Smith (Katchouro 89).

Subs Not Used: Hall, Duke.

Booked: Derry, Brown, Sandford.

Goals: Devlin 4, Smith 64.

Att: 22,874

Ref: G Frankland (Middlesbrough).