Leinster 32 Biarritz 6
Leinster went on a seven-game unbeaten run in last season's Heineken Cup before capitulating 21-14 to Perpignan in a Lansdowne Road semi-final but the same venue saw them back to their best with a four-try 32-6 success in their Pool 3 opener over French side Biarritz.
Two tries and a man-of-the-match performance from centre Shane Horgan eased them to the top of their Pool.
These sides last met eight months ago when the Lions tamed the visitors 18-13 in Dublin.
Just two-and-a-half minutes were on the clock today before O'Meara punished an infringement from opposite number Dmitri Yachvili with a 24-metre penalty.
Gordon D'Arcy set up field position for the imposing Horgan to release out-half Christian Warner galloping down the left wing in the eighth minute, but the Australian's inside pass five metres from the Biarritz line slipped forward.
Yachvili proved to be the Basque side's only source of points throughout the afternoon and after a period of dominance he dropped a goal in the eighteenth minute.
Crucially Biarritz flanker Olivier Nauroy walked during Leinster's own period of supremacy as English referee David Pearson yellow-carded the Frenchman for preventing a Leinster release of the ball illegally.
Horgan managed to chip through past winger Philippe Bernat-Salles and outpace him to collect and score a first Leinster try 10 minutes later with scrum half Brian O'Meara unfortunately wide with the conversion attempt.
An inspired Horgan stormed over again on 35 minutes when he intercepted centre Guillaume Bousses' lazy pass just short of the halfway line.
Biarritz, minus the power and poise of flanker Serge Betsen, looked a beaten side at the turn of the half, facing into a 15-3 deficit.
There was little poise about skipper Jean-Marc Gonzalez's 46th minute lineout as five metres from his own line, a wayward throw found the grasp of Leinster back row Eric Miller and he gleefully powered over for a third Leinster try, converted well by O'Meara.
A first ever Heineken Cup try for young lock Ben Gissing sealed an impressive performance from coach Gary Ella's men and a bonus point on 66 minutes.
And victory came despite Ireland centre Brian O'Driscoll being banished to the sidelines for repeated infringing at rucks.
Yachvili kept Biarritz heads from dropping with a first penalty success from his two attempts with a quarter of an hour remaining, but it was all too much for Romanian Ovidiu Tonita who lashed out at Miller in the final four minutes and was lucky to stay on the pitch.