The visitors controlled the early exchanges and built a health lead but the Blues fought back through the boot of Leigh Halfpenny and a second half score from Gethin Jenkins but it wasn’t quite enough at the death.
The European Champions raced into an early lead at Cardiff City Stadium with Ireland duo Sean O’Brien and Rob Keaney both crossing in the opening eleven minutes.
Rob Kearney added the extras to stretch Leinster’s lead to fourteen, fair reward for their dominant opening.
Leigh Halfpenny kicked two long range penalties in quick succession after Leinster were twice guilty of not rolling away at the breakdown and Dan Parks’ drop-goal after 27minutes narrowed the deficit even further.
Halfpenny missed a third long range effort from the touchline just before the break which would have rounded off a controlling spell for the hosts. The visitors though had the last word of the first period, Sexton kicking his first penalty to take the score to 9-17 at the interval.
The second period was only four minutes old when Sexton added another three points but Halfpenny soon responded with an impressive third penalty of his own.
Gethin Jenkins’ try at the end of the third quarter brought the Blues right back into contention. The Blues were awarded a scrum five metres out after Casey Laulala’s neat chip through and a resulting penalty at the set piece was taken quickly by the hosts and Jenkins barged his way over from close range.
Halfpenny again was on form with the conversion, narrowing the deficit to a point with twenty minutes to play.
The full-back though was off target with two penalties in quick succession which would have pushed his side into the lead and that was soon punished by Leinster’s Fergus McFadden who kicked his side three points further ahead.
The Blues threw everything at the Irish Province in the closing minutes but couldn’t find a way through the European Champions’ defence.
