Leinster have centre Fergus McFadden to thank for claiming all the points in a tight Magners League game in Cardiff on Sunday.
McFadden kicked three penalties, two conversions and scored a try in a Man of the Match display that leaves Leinster top of the Magner's League table.
Star man McFadden missed his first chance of points when he pulled a penalty wide but after that error it was a virtuoso display from the 23-year-old.
Just five minutes later he scored a try, breaking free to touch down between the posts, ensuring an easy conversion.
A penalty followed and Leinster led by 10-0 after 18 minutes.
But the Blues hit back with a try of their own in the 20th minute, when Gary Powell finished off a flowing move in the corner.
Ben Blair had a poor day with the boot and his missed conversion was the first of many points passed up by the hosts.
McFadden kicked another penalty for Leinster before Blair missed another for Cardiff, stretching the European champions lead to eight points.
A Sam Warburton try, converted by Blair, narrowed the gap but McFadden scored a penalty right at the end of the half to lead by 16 points to 12 at the break.
Chris Czekaj scored a try less than a minute into the second half for Cardiff but Blair missed the conversion and a Bernard Jackman try, converted by McFadden restored the lead to Leinster.
A Shaun Berne drop goal looked to have sealed the game for Leinster but Ceri Sweeney kicked a late penalty for Cardiff.
Then, with time up, McFadden struck another penalty, which scraped the bar before dropping over, denying Cardiff even the consolation of a losing bonus point.