Wasps

Wasps raced into a 21-0 lead and their fourth try after 55 minutes gave them a 16-point advantage against the bottom team in Pool One.

James Haskell was sent off for Wasps after a late flurry of tries saw Quins trail 28-26 with 10 minutes left.

Then came James Chisholm's 80th-minute winner for Quins for their first victory in the competition this season.

One negative for Quins and England was an eye injury to full-back Mike Brown.

The 26-year-old Highlanders star announced on social media that he's signed a three-year deal with English club Wasps.

Sopoaga, who recently became a father for the first time, said it was a difficult decision to make.

"It's with a heavy heart that I announce that my family and I will be leaving NZ at the end of the 2018 season," Sopoaga wrote on Instagram.

The home side came into Friday's clash having learned that flanker Marcell Coetzee will be out for another nine months after returning to South Africa to have further surgery on a serious knee injury.

Wasps are injury-ravaged themselves with director of rugby Dai Young complaining of having to open their European campaign just five days after defeat to Saracens in the Premiership, while Ulster enjoyed an extra 48 hours' rest following their Pro14 win over Connacht last weekend.

Bristol's difficult start to life back in the top tier continued at the Ricoh Arena, where ruthless Wasps turned on the style and ran in 10 tries to join Bath and champions Saracens on 14 points.

Brilliant Wasps had the bonus point in the bag at half-time, with Tommy Taylor touching down off the back of a driving maul in the first minute as Bristol were swept aside on Sunday.

Elliot Daly, Jake Cooper-Woolley, Matt Symons and Christian Wade also went over in the first half as Wasps opened up a commanding 37-3 advantage at the break.

The Coventry-based side have invested heavily during the close-season and the returning Danny Cipriani was among the starting XV at the Ricoh Arena.

But Thomas Waldrom, the Premiership's top try scorer last season, and Will Chudley scored tries while Henry Slade contributed seven points to leave 2015-16 runners-up Exeter 17-8 in front by the break.

Jimmy Gopperth's try had kept Wasps in it, though, and he added seven from the tee in the second half, while scores from Dan Robson and debutant Tommy Taylor completed the turnaround.

In other matches former Wallaby George Smith's Wasps sealed their last eight place with the English club recording a crushing 51-10 home victory over Irish side Leinster.

Johnston suffered an injury while with Samoa during the build-up to last year's World Cup.

And Wasps say that subsequent injuries meant the 29-year-old was unable to train fully or play a first-team game during his five months with the club.