Two through - but all to play for

But the other three qualifiers remain in the melting pot with head-to-head contests at the Twickenham Stoop and Stade Yves du Manoir set to decide two more Pool winners to be joined by three of the Heineken Cup Pool runners-up in April's knock-out stages.

Harlequins and Bayonne clash in Twickenham for Pool 1 honours with the Pool 3 spoils at stake in the Montpellier and Exeter Chiefs contest in the South of France.

The Stoop showdown comes after Harlequins won at I Cavalieri Estra with a try bonus point while Connacht Rugby stunned Bayonne with a 35-21 triumph at Stade Jean Dauger.

"I was delighted for Connacht coach Eric Elwood and his team when they won over in France last weekend but they did not really do us any favours," said Harlequins' Director of Rugby Conor O'Shea, a former club and country team-mate of Elwood.

"All we are focusing on is the knowledge that if we win against Bayonne on Saturday evening then we are through to the quarter-finals and with a home tie.

"But lose and we are out. That is the nature of the Amlin Challenge Cup and the situation in our Pool and the bottom line is that we simply cannot afford to lose.

"The main thing is that we are in the position we want to be with our destiny in this tournament in our own hands. We want to qualify for the last eight and we want to be at home in the quarter-finals.

"We have now won our last six matches in all competitions and playing some pretty good rugby.

"We also have a fine home record in recent times and we are both proud of that record and keen to keep it going.

"However, we are well aware that Bayonne have beaten some top sides like Castres Olympique, Toulon and Stade Francais Paris in recent Top 14 matches and they are a side who play good rugby, are very physical, have good ball carriers and players like fly half Benjamin Boyet and others at the back such as Johan Pietersen and Pepito Elhorga who can cause problems for anyone.

"They certainly have a big pack, whoever they select, and it promises to be a fascinating game."

While Harlequins will be playing their 83rd European tie - 49 of those in the Heineken Cup - Exeter Chiefs will be playing just their sixth European match with the lure of reaching the knock-out stages in their debut season.