Leinster's bid to claim top seeding for the knockout stages of the Heineken Champions Cup was buttressed by an ultimately convincing win over Lyon in Dublin on Sunday afternoon.

The prospect of a shock victory was but a false promise when Ireland took a 12 points lead into the break in the opening match of the World Rugby U-20 Championship in Perpignan.

Ireland, ever-present in the tournament since it started in Wales in 2008, will face a baptism of fire this evening when they open their World Rugby U20 Championship campaign against France at Stade Aime Giral.

Romain Ntamack, son of former French star Emile, led the way as France opened their Six Nations campaign with a win but only after they held off a spirited Irish recovery.

Ireland 27 France 22: Not a performance to shout about, but Ireland’s U20s did just about enough to make it three wins from three in this year’s Six Nations at Donnybrook last night.