Manchester  - Manchester United will take a narrow advantage into the second leg of their Champions League semi-final against Arsenal after edging out the London side 1-0 at Old Trafford on Wednesday.

The holders dominated the match for long periods but in the end only had an early header from John O'Shea to show for their superiority.

The two sides will play the second leg at the Emirates Stadium next Tuesday.

With only one goal between them, Arsenal will fancy their chances of progressing despite being outplayed for much of the match at Old Trafford.

Cristiano Ronaldo smashed a shot onto the crossbar midway through the second half, while Manuel Almunia had to make several excellent saves to prevent United taking a bigger lead into the second leg.

United had threatened the Arsenal goal a couple of times before making the breakthrough and the only surprise was that it came through the unlikely figure of O'Shea.

Michael Carrick worked his way to the byline after a corner and his deflected cross was headed into the net by O'Shea.

Ronaldo headed a good chance straight at Almunia, while Cesc Fabregas shot straight at Edwin van der Sar.

Wayne Rooney fired a shot just wide and Ronaldo then smashed a stunning effort onto the crossbar but United were unable to extend their lead.

On Tuesday Chelsea played to a goalless draw at Barcelona in the other semi-final game.  (dpa)