Bordeaux-Begles made a dream start to their Champions Cup campaign on Friday with a 41-5 away thumping of Connacht in Galway, while Northampton won 28-19 at Glasgow as the competition got under way.
France wing Damian Penaud played a starring role for Bordeaux, notching the visitors' second try to give his side a 12-5 halftime lead after Romain Buros had opened the scoring before Shamus Hurley-Langton hit back for Connacht.
The Top 14 club dominated the second period, with Buros' second try sealing a bonus point.
Pablo Uberti also touched down twice, Bordeaux were awarded a penalty try and Maxime Lucu kicked two conversions and a penalty.
Bordeaux, who sit seventh in the French top flight, are next in Pool 1 action a week on Saturday at home against Bristol.
They had only won one of their 10 matches in the competition across the two previous seasons.
"It was a test of character," said scrum-half and captain Lucu.
"We were promised hell and we wanted to show that we're progressing and that we're coming to win because we had a little difficulty during the previous campaigns."
The loss was a fourth defeat in five matches in all competitions for Connacht, a worrying run of form which has seen the Irish province ship 22 tries.
Northampton eased to victory in their Pool 3 opener in Scotland, despite a late rally from Glasgow.
Tommy Freeman scored two tries, with England's Courtney Lawes also dotting down.
All of Saints' tries came in the first half, after Argentina wing Sebastian Cancelliere's interception effort had given Glasgow an early lead.
Fly-half Fin Smith kicked 13 points and his two penalties put Northampton 28-5 ahead and they held on despite Ollie Smith's score and a late penalty try for the hosts.
Record five-time champions Toulouse kick off their campaign on Saturday against Cardiff, while holders La Rochelle start their bid for a third straight title with a repeat of last season's final against Leinster on Sunday.