Ben Murphy crowned a midweek contract extension by running in a Challenge Cup hat-trick as Connacht dished out a hammering to Lyon at Dexcom Stadium.
It takes his haul to seven tries in ten matches since his summer move from Leinster.
More importantly, the win guarantees top spot in Pool 1 even before Connacht head to Cardiff next weekend for the final game.
They ran in nine tries and while the French crossed the line three times, Connacht did enough to prevent them getting a fourth and keeping the pool alive until the final round.
Pete Wilkins' men bossed matters from the start and opened up a 19-3 lead after 18 minutes against a Lyon side who made 14 changes to the team which edged out Perpignan in a home relegation tussle last weekend.
Connacht got a dream start when captain Cian Prendergast intercepted a pass from Italian scrum-half Martin Page-Relo as Lyon attacked and he quickly sent Murphy away from the 22 with the scrum-half scoring under the posts when he managed to escape the clutches of winger Vincent Rattez to score under the posts after less than two minutes.
Page-Relo pulled back a penalty for a Lyon side who also came into this contest having won both their opening games when he converted from the right after Dave Heffernan was pinged for a maul offence to make it 7-3 after 12 minutes.
Lyon built on that but when flanker Marvin Okuya went offside despite warnings from referee Hollie Davidson when they looked set for a 50:22, Connacht made them pay. Out-half Josh Ioane found touch five metres from the line down the left and after Prendergast won the lineout, Connacht got the drive before No.8 Sean Jansen peeled away to score after 15 minutes.
Three minutes later, another good drive off a lineout ended after a few phases with tighthead Finlay Bealham getting over, with Ioane’s conversion making it 19-3.
However, Lyon hit back and while they butchered a couple of promising lineouts in the corners as Joe Joyce and Prendergast pilfered, the French got the set-piece right after 23 minutes and Fijian hooker Sam Matavesi got over, with Page-Relo converting from the right to cut the gap to 19-10 after Connacht lock Oisin Dowling had been binned.
Ioane added a penalty six minutes from the break and then played a part in a a turnover along with Bundee Aki that saw Connacht counter with a penalty and a few phases off the lineout. Eventually Aki, Ioane and Chay Mullins combined to send Murphy over for his second try and wrap up the bonus point.
Fijian winger Semi Radradra was binned for taking out Mullins after the pass as Lyon started the second-half 27-10 behind and down a man.
Interval replacement Josh Murphy scored a minute and a half after the restart and then Aki and Chay Mullins combined to send Murphy through for his hat-trick to lead 37-10 after 46 minutes.
Thibaut Regard responded for Lyon but Connacht were on top in all the key areas and they extended their lead when another replacement Jack Aungier bulldozed over after another good lineout drive after 54 minutes.
A try from replacement hooker Guillaume Marchand 11 minutes from time gave Lyon the prospect of a try bonus point, which would have kept the pool alive to the final round.
But it was Connacht who finished on a high with replacement hooker Dylan Tierney-Martin getting their eighth try seven minutes from the end.
Replacement scrum-half Caolin Blade got over in the final play but the score was scratched on review when Jordan Duggan was pinged for taking out a man off the ball.
Connacht should probably have killed the game and not allowed Lyon pinch a bonus point but as it turned out they kept the ball alive and got over for a ninth try from flanker Shamus Hurley-Langton with the clock four minutes in the red.
SCORERS:
Connacht: Tries: Ben Murphy (3), Sean Jansen, Finlay Bealham, Josh Murphy, Jack Aungier, Dylan Tierney-Martin, Shamus Hurley-Langton.
Cons: Josh Ioane (2).
Pen: Ioane.
Lyon: Tries: Sam Matavesi, Thibaut Regard, Guillaume Marchand.
Cons: Martin Page-Relo (2), Martin Meliande.
Pens: Page-Relo.
Connacht: Santiago Cordero; Chay Mullins, Piers O'Conor, Bundee Aki, Shane Jennings; Josh Ioane, Ben Murphy; Peter Dooley, Dave Heffernan, Finlay Bealham; Oisin Dowling, Joe Joyce; Cian Prendergast (c), Shamus Hurley-Langton, Sean Jansen.
Replacements: Josh Murphy (for Dowling 41), Jack Aungier (for Bealham 53), Dylan Tierney-Martin (for Heffernan 53), David Hawkshaw (for Jennings 53), Caolin Blade (for B Murphy 60), Peter Dooley (for Duggan 60), Paul Boyle (for Joyce 60), Cathal Forde (for Aki 72).
Lyon: Alexandre Tchaptchet; Semi Radradra, Josiah Maraku, Thibaut Regard, Vincent Rattez; Fletcher Smith, Martin Page-Relo; Hamza Kaabeche, Sam Matavesi, Irakli Aptsiauri; Félix Lambey (c), Tomas Lavanini; Steeve Blanc-Mappaz, Marvin Okuya, Maxime Gouzou.
Replacements: Guillaume Marchand (for Matavesi 48), Jermaine Ainsley (for Kaabeche 48), Pierre-Samuel Pacheco (for Okuya 55), Alfred Parisien (for Regard 55), Charlie Cassang (for Page-Relo 60), Killian Geraci (for Lambey 60).
Referee: Hollie Davidson (Scotland).
