Northampton boss Paul Grayson wants his Heineken Cup heroes to forget about their prolonged domestic relegation battle - at least for 24 hours.

Grayson used words like "incredible" and "bizarre" after Saints tore European rugby's form book to shreds to stun quarter-final opponents Biarritz in San Sebastian.

The 7-6 triumph - secured by a Robbie Kydd interception try that Carlos Spencer converted - means Northampton and Wasps will contest the firstall-English Heineken Cup semi-final since Leicester beat Gloucester in 2001.

The April 22 tie, at Coventry City's 32,000-capacity Ricoh Arena, is a repeat of the 2000 quarter-final clash between the clubs.

Grayson kicked 20 points on that occasion as Saints triumphed 25-22 and then went on to lift the trophy by defeating Munster at Twickenham.

While shell-shocked Biarritz coach Patrice Lagisquet has already written off Northampton's chances of toppling the 2004 European champions, Grayson urged his players to savour their remarkable victory.

He said: ``I think we were 100-1 in a two-horse race, but that's what sport is all about.

``In the big picture, we didn't really think about getting a win because on paper, Biarritz should realistically have won.

``We wanted to frustrate them and keep the score close, because you never know when you are going to get something like an intercept to turn the game.''

Saints are currently bottom of the Guinness Premiership with only three games remaining, but Grayson added: ``The Premiership will be what the Premiership will be.

``Right now, the players deserve 24 hours to bask in the glory of a pretty incredible victory.

``We've got a massive game away to Newcastle next Sunday, but right now we don't even want to think about that.

``We have made the Heineken Cup semi-finals against all the odds. It proves that on any given day, sport can turn up some bizarre results.''

Lagisquet though, retorted: ``I am disappointed, angry and frustrated. Going into the game, no way could I see Northampton beating us.

``At half-time, I said we had to be patient and put away our chances, but we didn't do it. I would be extremely surprised if Northampton beat Wasps in the semi-final.''

Leicester, meanwhile, ensured England will have a record three semi-finalists by defeating French Championship leaders Stade Francais 21-20 at Welford Roadthanks to substitute wing Tom Varndell's converted try eight minutes from time.

In stark contrast, French clubs have failed to produce a semi-final contender for the first time, although Heineken Cup attention switches to the meeting rooms this week with likely confirmation of a French tournament boycott next season and English clubs possibly following suit.

Tigers head coach Pat Howard said: ``The treble is our goal. It is a very hard goal, but we believe we have a squad that can attempt it.

``We want to fight on all fronts, and you have got to aim high in whatever competition you take part in.''

Leicester beat Llanelli in the semi-finals five years ago thanks to a last-gasp Tim Stimpson penalty, but the Scarlets will have already noted that Tigers' two previous Walkers Stadium visits in European competition produced defeats against Toulouse and Bath.

Howard added: ``I appreciate we are very close to home in the semi-finals, but at this level being home or away means nothing. Besides, we haven't won at the Walkers Stadium.''

Leicester skipper Martin Corry said: ``I think I aged quite a few years at the end. It was one of those tough ones that you couldn't really bear to watch.

``It was tremendous guts from the players to hold on. We made some mistakes, but in terms of determination and courage, it was 10 out of 10 from our players.''

In the European Challenge Cup, tries by Dan Scarbrough and Kameli Ratuvou sent Saracens on their way to a 23-19 victory against Glasgow Warriors, setting up a semi-final appointment with Bath later this month.