Gareth Anscombe was the star man for the Blues as he scored a total of 20 points including a mesmeric solo try, three conversions, and three penalties.
Olly Robinson and Tomos Williams were also on the board as the Blues came out on top despite Lyon tries from Loann Goujon and Quentin Delord.
“The whole coaching group, everyone who came to Lyon as part of the team, and the supporters are so proud of this team. They produced a fantastic performance,” said Blues head coach John Mulvihill.
“We knew if we opened the game up and moved the ball around then we would have some success and we wanted to keep the ball away from the Lyon forwards. They have a great scrum and line-out.
“I thought Gareth and Tomos were outstanding and they both produced big displays, but every single player can be proud of their performance.
“Jarrod Evans had his moments too in unleashing the backs outside him.”
A try from No 8 Goujon and a conversion and penalty from Lionel Beauxis gave Lyon the perfect start, but once the Blues got their running game going they were soon on top.
First, Williams dummied his way past the first line of defence and popped the ball up to Robinson. Williams then scored one of his own after Ellis Jenkins intercepted a pass and raced clear.
Anscombe converted both tries in impressive fashion.
Two more penalties from Beauxis gave Lyon a 16-14 interval lead, but Anscombe responded with a brace of his own as the Blues hit back when the game resumed.
The Wales star, playing at full-back, then cut clean through from half-way to score a wonder try that he also converted to stretch the lead to 11 points with another conversion.
Lyon scored a try through Delord with 90 seconds to play to seemingly secure a losing bonus-point, but a Jenkins turn-over penalty in front of the posts allowed Anscombe to steal it away from them with the final kick of the
match.
“We talked about our return to the Champions Cup a lot in the build-up to the game and it was a big focus for us. We want to do this competition proud,” Mulvihill added.
“It means a lot to us to play against the best teams in Europe and this is a fantastic tournament. The physicality of the games is huge and we stood up to that.
“It’s a great result for us and hopefully it means we can pack out Cardiff Arms Park next Sunday when Glasgow visit because that’s going to be another big game for us.
“Hopefully we can build on this win.”
