Scotland full-back Blair Kinghorn scored two tries on his Toulouse debut as the record five-time winners hammered Cardiff 52-7 in the Champions Cup on Saturday.
Kinghorn only arrived at the French club this week after moving from Edinburgh for a hefty transfer fee and took his new side, captained by France scrum-half Antoine Dupont, to the top of Pool 2.
Wingers Matthis Lebel and Arthur Retiere, lock Richie Arnold as well as back-rowers Anthony Jelonch and Alban Placines crossed for the Top 14 champions, as they put their rusty league form behind them.
"I think he'll be happy with his first game," Dupont said of Kinghorn.
"We all knew his individual qualities; we had no doubt about that. We need a player of his quality," the half-back added.
Twenty-year-old No 8 Mackenzie Martin scored the Welsh side's only try, making only his third senior appearance, highlighting the lack of experience and spending power at the 1996 finalists.
Bath also made a winning start in the group after an impressive 37-14 comeback victory over Ulster.
The English side, 1998 winners, were behind the 1999 champions by six points at the break before four second-half tries.
- 'Cool' comeback -
Earlier, England centre Henry Slade landed a conversion with the last kick of the game to give Exeter Chiefs a dramatic 19-18 win at Toulon.
Three-time winners Toulon appeared to be in line for a winning start as they opened up an 18-5 lead at half-time, thanks to tries from tries from Beka Gigashvili and Ben White.
"It's pretty cool to come here and get a win, especially after the first half," Slade told TNT Sports.
"To keep them scoreless in the second half, the way we came back at the end, was really pleasing."
An injury to replacement scrum-half Baptiste Serin, however, in the 56th minute shifted the balance and Exeter, champions 2020, closed the gap when Max Norey added to Harvey Skinner's first-half try.
Exeter then camped on the Toulon line and with 40 seconds left on the clock, the video referee confirmed that flanker Jacques Vermeulen had touched down for another Chiefs try.
Slade's conversion from five metres in flew between the posts to seal a thrilling victory.
Also on Saturday, Bayonne held two-time winners Munster 17-17 in the west of Ireland in the Basque outfit's first game in the top-tier competition.
The Bulls eased past Saracens 27-16 after the three-time winners had England No 8 Billy Vunipola sent off with half an hour of the game to play in Pretoria.
Later, Bristol Bears avoided a third comeback of the day thanks to Callum Sheedy's 85th-minute drop goal which claimed a 36-34 win over Lyon.
On Sunday, La Rochelle start their bid for a third straight title with a repeat of last season's final against Leinster after English Premiership leaders Sale host a much-changed Stade Francais.