Jacob Stockdale has offered an apology to Ulster fans over his second half error in Saturday's narrow 21-18 defeat to Leinster in the Heineken Champions Cup quarter-final. 

With Ulster leading 13-11 early in the second half, Stockdale made a blistering break, shrugging off a couple of tackles and powering into open country as he attempted to touch down and score a potentially critical try. 

However, the winger was far too cavalier when it came to applying the finish and, under pressure from Dave Kearney, let the ball slip out of his grasp as he went to touch down. 

Leinster's Adam Byrne scored at the other end shortly afterwards and the reigning champions went on to claim a narrow victory. 

Ulster head coach Dan McFarland refused to blame the loss on Stockdale's mishap, praising his winger's overall contribution, and citing a multitude of other factors to account for the defeat. 

But the crestfallen winger saw fit to offer an apology via his Instagram account, telling the Ulster fans that he let them down and they deserve to be looking forward to an European Cup semi-final. 

"I’ve had some incredible highs with Ulster rugby, but unfortunately yesterday was a low for me," Stockdale wrote.

"Sport can be cruel and sometimes you have to learn your lessons the hard way.

"To the Ulster fans I just want to say I am sorry, I let you down, the support we had yesterday was truly amazing and you deserve to be looking forward to a European semi-final."