PARIS — Four-time winners Leinster produced a stunning seven-try, 50-21 victory against Northampton in Dublin on Saturday to become the first team ever to qualify for the quarterfinals of the European Champions Cup after just four rounds.

Ireland center Gary Ringrose scored a hat-trick of tries as the home side blew away the team they beat in the 2011 final.

They moved to 19 points at the top of Pool 1, enough to guarantee them a place in the knockout rounds with two group games still to play.

"Games like that where you go up by 20 points early on, well then that's where our ruthless edge kicks in and we've got to keep going, keep pushing, keep scoring tries," said Leinster wing Dave Kearney, one of his team's scorers.

Toulouse also moved to within a heartbeat of the last eight with a 26-18 win at Montpellier while defending champions Saracens kept their hopes alive with a hard-fought 15-6 win at home to Munster.

Leinster, who won 43-16 in Northampton a week ago, ripped into the Saints from the first whistle, Ringrose charging down a clearance and going through for his first try in just the second minute.

When he added a second four minutes later, Northampton knew they were in for a long afternoon, further tries Tadhg Furlong and Kearney securing the bonus point before half-time.

Northampton battled hard but second half tries from James Lowe, Ringrose and Caelan Doris completed the rout.

Northampton stay second in Pool 1 on nine points, two ahead of Lyon who slipped to a 25-22 defeat at Treviso where Marco Lazzaroni's converted try eight minutes from time snatched the win for the Italians.

Toulouse all but booked their place in the quarter-finals with a 26-18 win at Montpellier.

A last minute try from Lucas Tauzin, a 71st minute replacement for South African World Cup winning winger Cheslin Kolbe, secured the bonus point for Toulouse who head Pool 5 with 18 points.

They are nine points clear of Gloucester who lost in a dramatic finale to Connacht in Galway.

Kolbe faces tests next week after picking up a rib injury when tackled by 130-kilo Fijian winger Nemani Nadolo.

"He has hurt his ribs and he is going to have it for a little while," said Toulouse coach Ugo Mola after the game.

France fly-half Romain Ntamack scored Toulouse's first try and they led 14-13 at the break with Montpellier compromised by a serious knee injury to former France number eight Louis Picamoles after just two minutes.

Australian lock Rory Arnold touched down twice in the second half before Tauzin's score in the right hand corner closed the contest.

Montpellier, who scored a try in each half, can no longer qualify.

"We turned into Santa Claus before the hour. We gave them two tries as gifts," said Montpellier's sporting manager Xavier Garbajosa.

The other game in Pool 5 brought a dramatic finish as Connacht scored twice in the last four minutes to dent Gloucester's hopes of keeping Toulouse in their sights.

The English side led 24-13 in the 76th minute but with Lewis Ludlow in the sin-bin, Connacht delighted the home crowd with converted tries from Shane Delahunt and Robin Copeland.

Champions Saracens scored twice late as they outmuscled Munster and kept their defense alive in Pool 4.

Trailing 6-3 after 65 minutes, Saracens took the lead when Scottish international wing Sean Maitland slithered in down the right.

England prop Mako Vunipola sealed the win when he crashed over from close range.

The game was marred by a mass brawl in the second half, sparked it seems by a comment made by a member of the Munster medical staff about Saracens hooker Jamie George.

Saracens are considering whether to make an official complaint against Jamie Kearns, the Irish province's chief medic.

"Something pretty bad was said at Jamie," said Saracens' director of rugby Mark McCall.

Munster stay second in the pool with 11 points, six behind French side Racing. Saracens are a further point back in third.

On a wet night in Scotland, Jules Favre and Levani Botia both scored in La Rochelle's win against Glasgow.

The Warriors had number eight Matthew Fagerson sent off for leading with his forearm in the build-up to a try that was subsequently disallowed and now face a tough route to the last eight. — AFP