Gloucester started last Saturday with only two men on the pitch and got off to their worst start when Vannes’ Romaric Camou cleared and found fellow winger Benmegal who dived brilliantly inside the first 50 seconds.
The Cherry and Whites had little time to compose themselves before hooker Theo Beziat overcame several weak challenges to head for the line once again.
The Frenchman was able to offload to Kiwi scrum-half Ruru, who dived one-handed to clear the hosts’ 14 in less than four minutes.
But the visitors reacted immediately and George Barton found a gap, allowing night skipper Harris to reduce the arrears.
But four minutes later Lulu restored the hosts’ two-point advantage when he leapt over a loose ball to dive from a yard after a good lineout.
It took Gloucester some time until half-time to get themselves under control and when Barton attempted to break through a tight gap, Beziat was sent to the bin with 10 minutes to play for foul play.
But they were unable to make their man-of-the-man pay as a sloppy end to the first half saw Vannes go into the gap 12 points ahead.
Seven minutes into the second half, some great play from right to left gave Benmegal their second goal from a corner kick, effectively putting Vannes out of sight.
Gloucester’s heads did not fall and after Reeves’ meandering run, scrum-half Charlie Chapman substituted Blackmore alongside him to find the gap and dive under the posts.
Vannes briefly lost their composure and after a fantastic dummy from Will Butler a pass through the middle allowed Jake Morris to score the simplest of tries into the right corner to make it a seven-point game.
The French club responded with Chateau powering through a driving maul and Gloucester’s Freddie Clarke was sin-binned for the remainder of the match for coming in from the wing.
A carbon copy of his fifth try just seconds later allowed Blanchard to add a sixth try to Vannes, who put his current poor domestic form to one side to inflict a bruising defeat on his less experienced opponent.
