A thunderbolt strike by Leroy Lita was enough to ensure Lee Clark had the happiest of 40th birthdays as his Birmingham City side claimed all three points at Elland Road.
The Blues striker struck with 14 minutes remaining to condemn a lacklustre Whites to a first defeat in seven Championship outings.
United could have few complaints with the result after putting in another disappointing shift to slump to their first home defeat since Hull City’s triumph in West Yorkshire on September 18.
The first half had been a lacklustre affair, enlivened only by the visitors’ assured look on the ball and fluid movement up front, something that led to the opening quarter belonged firmly to Lee Clark’s side.
Curtis Davies should have capitalised on City’s dominance on 11 minutes when he was presented with a great chance but could only head wide.
Steven Caldwell also fired over with a volley, while Marlon King – another Elland Road old boy – was only prevented from breaking clear on a couple of occasions by Lee Peltier’s last ditch tackles.
It took Leeds until the 22nd minute to threaten and even then Jack Butland was able to race from his line to avert the danger after Sam Byram had exchanged one-twos with El-Hadji Diouf and Michael Tonge.
Butland was rather more fortunate on 29 minutes when his legs kept out a Rodolph Austin swerving shot that had clearly deceived the England Under-21 goalkeeper.
That was just about it for the first half in terms of goalscoring opportunities, though United did have one let-off when Tom Lees appeared to nudge Leroy Lita in the back as the striker rose to meet a King cross three yards out but referee Graham Salisbury waved play on.
The second half started in much the same way as the opening 45 minutes had progressed with misplaced passes and poor decision making aplenty.
Nathan Redmond made a hash of an attempted volley after Lee Peltier’s clearance had gone straight to the Blues midfielder.
Diouf, who earlier had had a coke bottle thrown at him from the visiting seats, brought a stunning reflex save from Jack Butland on 70 minutes.
Lita then put the vistors ahead with a thunderous 30-yard shot on 76 minutes after a clever dummy from King, who late on struck the bar with another fine effort.