Racing 92 took a big step towards the Champions Cup quarter-finals with a 36-26 win over Leicester Tigers on Sunday, while two-time winners Munster hammered French champions Castres.
Saracens joined France's Racing in making it three wins from three with an astonishing second-half revival to thrash Cardiff Blues 51-25.
Racing claimed a bonus points within 35 minutes as international backs Virimi Vakatawa, Juan Imhoff and Simon Zebo crossed as well as inexperienced back-rower Baptiste Chouzenoux.
Scotland fly-half Finn Russell was instrumental as his side played an expansive brand of rugby which produced a fifth and final try to secure victory ten minutes from time.
France prop Eddy Ben Arous left the field on a stretcher with a neck injury and went to a nearby hospital for further assessments.
Coach Laurent Travers was impressed by his team's ability with ball in hand but expected more from his side.
"Our attack was very good so we're not going to be fussy but we left three tries out there," he said.
"Sometimes we have to be more clear in our thinking to know when to play and when to keep it tight," he added.
Tigers left the French capital with their own bonus point, which pleased coach Geordan Murphy.
"Tough place to come and always good to get a bonus point on the road. Disappointed we couldn’t get more from the game but you’ll take a point," the former Ireland winger said.
Racing top Pool 4 with 14 points from a possible 15 and are in a strong position to qualify for the quarter-finals, while Tigers are eight behind and need to gain their revenge at Welford Road next Sunday to hold any hope of a last eight spot.
At Thomond Park, two JJ Hanrahan penalties was all Munster had to show from the first half but they stepped up a gear in the second half of a 30-5 rout with tries from Rory Scannell, CJ Stander and Hanrahan.
Munster lead Pool Two with 11 points, three more than Gloucester.
Another former two-time champion, Saracens, survived an early scare from Welsh side Cardiff Blues in north London.
Tries from Blaine Scully and Matthew Morgan gave the Welsh side a deserved 18-13 lead at the break.
Saracens hit back in the second half with Ben Earls crossing twice to put them ahead.
Sean Maitland also scored two tries and there were touchdowns for Ben Spencer and Christian Judge as Saracens added 38 points in the second half, picking up a bonus point in the process.
They top Pool Three with three wins from three.