Cardiff ... 30 Leinster ... 17 An early second-half blitz when Leinster were down to 14 men left last year's Celtic League champions on the verge of crashing out of this season's competition.

Outhalf Iestyn Harris' 20 points made sure of the Welsh side's first home win.

Despite Leinster's efforts to spread the ball, the first half was a shapeless affair, marked by some aimless kicking and the constant blast of Scottish referee Iain Ramage's whistle.

Leinster prop Niall Treston was sin-binned just before half-time and was still absent as Cardiff rattled 15 points in the opening exchanges of the second period.

A brilliant over-arm pass by skipper Martyn Williams in midfield allowed left wing Anthony Sullivan to dive in at the corner.

Then it was livewire flanker Williams who won a turn over on the halfway line and, after a darting run by scrum-half Ryan Powell, popped up to finish the move.

Leinster centre David Quinlan grabbed a loose ball in the Cardiff 22 to put lock Aidan Kearney over. But the holders were unable to maintain the pressure and Harris' boot had the final say.

LEINSTER: Warner; Lewis, Horgan, Quinlan, Darcy; Dunne, O'Meara; E Byrne, Smyth, Treston, Gissing, Kearney, McCullen, Toland, Dillon.

CARDIFF: Van Vuuren; Walne, J Robinson, Muller, Sullivan; Harris, R Powell; Payne , Woods, G Powell, Sennekal, A Jones, Appleyard, Baugh, M Williams.