Leicester, Toulon and Munster all secured Heineken Cup wins on Sunday, while Sale Sharks were mauled by Montpellier in France.
Leicester kept their European hopes alive with a vital 39-22 victory over Ospreys at Welford Road.
Three tries in the final eight minutes from Toby Flood, Ben Youngs and Manu Tuilagi added to Tuilagi's first half score to give the Tigers a much-needed bonus point from the must-win encounter.
Flood added a further 19 points with the boot in a superb kicking display, while Ospreys' points came through Ryan Jones' second-minute try plus 17 points from fly-half Dan Biggar.
Ospreys grabbed the lead in the second minute when Ryan Jones drove over from close range and Biggar converted to put his side 7-0 up.
Ten minutes later the fly-half extended the Welsh side's advantage with a fine long-range penalty from the halfway before Toby Flood finally booted Leicester onto the scoreboard in the 28th minute.
Leicester levelled the scores three minutes later when some superb link play from the Tigers backs put Tuilagi in on the right for a beautifully worked try and Flood converted.
Biggar put his side back in front almost immediately after the break but Flood put the Tigers in front for the first time with two penalties and then extended the lead on 49 minutes with a 47 metre effort.
Biggar hit back with two of his own to put his side back on level terms going into the final quarter before Flood wrested back the lead with a superb 53 metre kick with 14 minutes to go.
Moments later the England fly-half opened the flood gates with a brilliant interception to all but guarantee the win and Youngs and Tuilagi followed in quick succession to seal the bonus point.
Jonny Wilkinson kicked 17 points as Toulon made it two wins from two in Pool Six of the Heineken Cup with a bruising 22-14 win over Cardiff Blues at the Arms' Park.
The Blues, playing their first European game at their traditional home since 2009, made a superb start when Leigh Halfpenny went over for the opening try inside two minutes.
The Welsh side's magnificent defence flustered the visitors, but their power eventually told.
Wilkinson kicked five penalties and converted man-of-the-match Steffon Armitage's try, meaning Halfpenny's three penalties were not even good enough for a losing bonus point for the Blues.
But the game's major talking point involved Armitage's brother Delon, who escaped without receiving a card for a high no-arms tackle on Blues' centre Gavin Evans during the first half.
The England full-back led with his shoulder and caught the Cardiff centre, who was stretchered off and sent to hospital for checks, on the head.
Munster steamrollered Edinburgh 33-0 in Pool One with three tries in the final 10 minutes as they returned to winning ways at Thomond Park.
A late forwards-led flurry saw Peter O'Mahony, Sean Dougall and Damien Varley all touch down as the hosts seized upon an unlikely bonus point.
With the injured Ronan O'Gara watching on from the stands, his deputy Ian Keatley landed two penalties from four attempts to give the hosts a 6-0 interval lead.
There was more for the home crowd to get their teeth into in the second half, with Conor Murray's 51st-minute try giving Rob Penney's side some breathing space.
Hammered 45-0 at home by Saracens in the opening round, Edinburgh allowed their heads to drop and Munster took advantage late on as they ended a run of three straight defeats.
Sale Sharks' Heineken Cup hopes suffered a blow as they were beaten 33-18 by Montpellier in France on Sunday.
The Sharks took an early lead with a try from Mark Cueto but Montpellier's forwards soon took control in wet conditions and tries from Francois Trinh-Duc, Timoci Nagusa and Julien Tomas secured victory for the hosts.
Sale got off to the ideal start with Danny Cipriani - handed the fly-half shirt following his game-changing burst against Cardiff last weekend - chipping into the corner for Cueto to touch down in the third minute.
But as the half wore on Montpellier's forwards began to exert their power up front and a series of errors in the wet conditions from Sale cost them possession and field position.
Martin Bustos Moyano landed four penalties to give the hosts a 12-8 half-time lead with Rob Miller kicking one for Sale.
Miller landed a further penalty after the break but Montpellier's superior power up front was decisive as their pack decimated a Sale scrum, leaving Trinh-Duc to stroll over to score in the 49th minute.
Minutes later Nagusa had the pace to finish off a breakaway try before the hosts scored their third try when Trinh-Duc's deft chip and collect set up a try for scrum-half Tomas.
Bustos Moyana landed both conversions to end with an 18-point haul while substitute Richie Vernon grabbed a consolation try for the Sharks.
