The Saint threw plenty of punches, but despite failing to stop his French opponent, Groves looked positively on his night's work.
He told Sky Sports: "He took an awful lot of punches. We knew it was going to be tough tonight, we talked about the come down from the historic last fight. I always say I deal with pressure well, and tonight I've got a bit of success to go with it.
"I want to knock people out. I didn't manage to do it tonight, but I gave it a real good go. I think all the fans here tonight appreciate that, so that's why they come out to support me.
"I didn't want to run out of steam. I felt in great condition but you always have to be cautious with a guy who has never been stopped."
Groves could be set for another shot at the world title shot later this year, against WBC champion Anthony Dirrell.