Celtic League champions Leinster will aim to turn the clock back two years when they tackle European champions Leicester in Sunday's Heineken Cup quarter-final clash at Welford Road.

Leinster were the last team to topple the Tigers on home soil - a 32-10 Heineken Cup group win - since when Leicester have reeled off 36 successive victories in all competitions.

Leicester though, were already out of Europe that January afternoon, and Leinster coach Matt Williams knows it will be an entirely different story this time around.

"They had very much a second-string side out - they were out of the tournament - yet we still know how hard it was to beat them," Williams said.

"This time they will be at full-strength, but these are the days that you live for. It will be a great day and a great occasion, win, lose or draw."

Leinster hold a 3-2 lead over five previous European meetings between the teams, and Leicester go into battle following back-to-back defeats against Llanelli and Harlequins, but Australian Williams accepts that a huge task lies ahead.

"When I was coaching in the Super 12 tournament, Auckland were the outstanding team - they were the ones we always wanted to play," he added.

"And it is much the same with Leicester. They are the Heineken Cup champions - they are the ones you want to test yourself against.

"We are under no illusions about hard it is going to be on Sunday - this will be the biggest test that this Leinster team has ever faced.

"Leicester are a wonderful side with great talent, but we will go there with spirits high and plenty of confidence."

Tigers are set to welcome back England star Austin Healey from suspension, while Leicester old boy Eric Miller can expect a warm welcome when he returns to the east midlands with Leinster.

Scotland ace Gregor Townsend will spearhead Castres' attempt to reach their first Heineken Cup semi-final in an all-French affair against Montferrand on Saturday.

And Castres have received a huge boost after their Ivory Coast forward Ismaela Lassissi won his appeal against a 12-month ban imposed by tournament disciplinary chiefs following a biting allegation.

Lassissi, whose appeal was heard last night, is now free to face Montferrand.

He had been accused by Munster of biting their Irish international prop Peter Clohessy's arm during a group game between the teams on January 12.

Castres wing Ugo Mola, the competition's top try-scorer this season, has been ruled though because of a hip injury.

Castres beat Montferrand 39-30 in the French Championship earlier this term, and Townsend is seeking a repeat performance before linking up with the Scotland squad for next Saturday's Lloyds TSB Six Nations opener against England at Murrayfield.

"It has been a funny old season for us," Townsend said.

"Our coach was sacked halfway through it, but then winning at Harlequins in the Heineken Cup was a watershed for us.

"We showed how we could play, and we have maintained that level in the tournament since then.

"We will be totally aware of Montferrand's strengths. They are the best counter-attacking team in Europe, a dangerous side that always tries to play positive rugby."

Saturday's other quarter-final is also in France, with last season's runners-up Stade Francais hosting Munster at their Paris base of Stade Jean Bouin.

Stade pipped Munster 16-15 in the semi-finals last term, and start as favourites to make the penultimate knockout stage for a third time in four seasons.

Llanelli coach Gareth Jenkins has dismissed Bath's patchy Premiership form as an irrelevance ahead of Saturday's Heineken Cup quarter-final clash at the Recreation Ground.

Bath, despite losing seven league games from 12 starts this term, roared into the European knockout stages as top seeds after winning all six group games, including beating strongly-fancied French challengers Biarritz home and away.

Llanelli, in contrast, grabbed the final last-eight place by defeating Heineken Cup holders Leicester and then progressing courtesy of a superior try-count to Ulster.

The fear for Bath fans is that their team's league deficiencies will return and haunt them in front of a sell-out 8,200 crowd this weekend.

Jenkins, though, is having none of it, fully recognising Bath's European pedigree which was highlighted by them lifting the trophy in 1998.

``You have to look at what Bath have done in their most recent games and that shows two Heineken Cup wins against Swansea and Biarritz,'' Jenkins said.

``That is the current form we are taking note of - nothing that has gone before.

``But on the other hand, there are not a lot of unknown elements to this game for us, which there would be if we were travelling to France, for example.

``We are familiar with the Bath players and we are familiar with the Bath ground.

``And this is a massive match on two fronts. First, there is the fantastic kudos at stake, and then everyone is aware of the financial aspect of going further in the Heineken Cup.''