Cristiano Ronaldo’s first goal of the Barclays Premier League campaign secured a fifth successive league win for Sir Alex Ferguson’s side at St Andrews.

But his side were pushed all the way by Steve Bruce’s battlers before climbing back into second spot - two points adrift of Arsenal who also have a game in hand.

Ronaldo, in what was his 100th league start, settled the issue six minutes into the second half and United have now kept five successive clean sheets in the competition since losing the Manchester derby.

It was also their fourth 1-0 league win of the campaign and they have achieved their lofty position in the table despite scoring only seven times in eight games.

With the wealth of strikers at their disposal, that record will surely improve sooner rather than later and Carlos Tevez looked sharp.

But Birmingham can consider themselves unfortunate not to have claimed a share of the spoils and were the more threatening side in the opening 45 minutes.

United seemed nervous at the back during the first half apart from a majestic performance by Rio Ferdinand.

The irony of the outcome would not have been lost on Bruce after Blues were heavily criticised for a defensive performance in earning a goalless draw at Liverpool last weekend.

On this occasion, his side caused the Red Devils all kinds of problems. Olivier Kapo and Gary McSheffrey created several good chances - but ended up with no reward.

Clearance

Birmingham made an enterprising start and United keeper Edwin van der Sar was twice called into action in the first two minutes.

A mistake by Paul Scholes allowed Cameron Jerome a free run at the United goal and his fierce left-footed drive from 20 yards out was turned around the post by the Dutchman.

Then Van der Sar had to react smartly to cling on to Franck Queudrue’s glancing header from the resulting corner by Sebastian Larsson.

The first real threat to the home side came when a long clearance from Van der Sar found its way to Wayne Rooney in plenty of space to the right of the Blues box.

The England striker tried to chip Northern Ireland keeper Maik Taylor but he had come racing off his line to narrow the angle and managed to block his attempt.

United were forced into a half-time substitution with Van der Sar apparently still troubled by the first-half ankle knock and replaced by Tomasz Kuszczak.
After 51 minutes, Ronaldo broke the deadlock with his first league goal of the campaign.

There seemed little danger when Ferdinand played the ball forward just inside the Blues area but Queudrue hesitated when he should have cleared and Ronaldo took full advantage.

He surged forward and coolly took the ball around Taylor before firing home. Birmingham tried to retaliate and Kuszczak needed two attempts to gather a low volley from McSheffrey.

But the former West Brom keeper made an excellent save to turn another McSheffrey pile-driver around the post after it took a deflection off Ferdinand.

McSheffrey was only just off target with the resulting inswinging free-kick from a narrow angle.

Ronaldo could have settled the issue but dragged his shot just wide and in the last few seconds Kuszczak kept out a drive from Blues substitute Garry O’Connor.