The Tigers knew they had to roar following a 42-13 drubbing by Pool One rivals Glasgow nine days ago - or face having their quarter-final hopes hanging by a thread.

And even though it was far from pretty, they delivered after flanker Brendon O'Connor scored an early try, before two Owen Williams penalties and then 16 points from second-half substitute Freddie Burns saw Leicester home 27-17.

Burns booted three penalties, then he claimed a 70-metre interception try after collecting Maxime Machenaud's pass to Chris Masoe, before converting the clincher as Leicester avenged a Champions Cup semi-final loss to Racing six months ago.

New Zealand superstar Dan Carter scored 12 of Racing's points through a try, two conversions and a penalty, while wing Juan Imhoff touched down five minutes from time, yet the reigning Top 14 champions never got going as Leicester made it 15 games unbeaten against French opponents at Welford Road since Biarritz beat them in January 2005.

The Tigers have still got it all to do in a group that also includes Munster, and their December back-to-back meetings with the Irish province could prove pivotal.

It was not all trouble-free for Leicester though, and there was a long delay near the end when full-back Telusa Veainu went down injured following an attempted tackle on Racing lock Francois van der Merwe before being carried off.

Leicester handed a home debut to Australia Test centre Matt Toomua, while prop Marcos Ayerza and lock Ed Slater returned up-front. South Africa international wing JP Pietersen also made the starting line-up after missing the Tigers' last three games.

Carter, Imhoff and Joe Rokocoko all featured for Racing, whose scheduled opening Champions Cup game against Munster in Paris last weekend was postponed following the death of Munster head coach Anthony Foley.

The trio were cleared of anti-doping breaches by the French Rugby Federation earlier this week after tests conducted following the Top 14 final victory over Toulon in Barcelona four months ago.

But Carter had barely touched the ball before Leicester struck in impressive fashion with a fourth-minute try after securing close-range lineout possession and then shipping the ball wide, patiently going through-phase play before scrum-half Ben Youngs found an unmarked O'Connor, who touched down wide out.

Carter then opened Racing's account through an eighth-minute penalty following an infringement by Leicester lock Dom Barrow, whose afternoon lasted only 10 more minutes before he went off following a clash of heads with his team-mate Dan Cole.

Racing had their moments in attack, but were flustered by a combination of poor handling and aggressive Leicester defence, and the Tigers punished them through two Williams penalties during the second quarter, although not before Toomua departed injured.

The game's scrappy nature did not worry Leicester, with the result far outweighing performance following their capitulation at Glasgow nine days ago, but they allowed Racing back in by conceding a soft try just nine minutes after the restart.

Carter scored it, courtesy of throwing two dummy passes and executing a hand-off on Youngs, yet Leicester were guilty of wafer-thin defending as they allowed the World Cup winner a ludicrously easy run.

Carter's conversion cut the deficit to a point, but then it became the Burns show as he kicked two penalties and converted his try for 13 points in six minutes, and Racing were finished, despite a late Imhoff touchdown that Carter converted, before Burns' 77th-minute penalty sealed the deal.