UK Football

GLASGOW, Aug 10 (Reuters) - Celtic made a shaky start to the defence of their Scottish Premier League title when they needed a second half Barry Robson penalty to beat 10-man St Mirren 1-0 on Sunday.

The champions failed to sparkle in a frustrating first half and they had to rely on keeper Artur Boruc to keep them in the game with a fine save just three minutes after the break.

Saints' Stephen O'Donnell played in striker Billy Mehmet at the edge of the box and his side-footed shot was touched onto the right post by the Polish keeper at full stretch.

A minute later, Saints keeper Mark Howard did well to dive and clutch a close range header from Gary Caldwell following a deep free kick from the left by Lee Naylor.

Celtic found Saints' defence difficult to penetrate until the hour was up and Jan Vennegoor of Hesselink pounced on an error by Will Haining who mis-cued an attempted clearance two metres outside the box.

The Dutch striker wrestled his way beyond Haining who was then ruled to have hauled him down to earn a hotly disputed red card.

Robson struck his penalty straight down the middle and although Howard managed to get a leg to the ball, it spun up and over the line.

St Mirren manager Gus MacPherson, unhappy with the penalty decision, told BBC radio: "I refuse to comment and give the limelight to the referee today - they like that."

In Saturday's opening day action, Celtic's arch-rivals Rangers won 1-0 at Falkirk.

Promoted Hamilton Academical face Dundee United on Monday.