"It's a great win; we wanted to see where we stood in relation to a terrific Monaco side, and we're very happy," Girard told reporters. "It was a wonderful night, with our fans pushing us all the way.
"We had some good fortune in attack and defence, but I never allow myself to feel that I've been beaten before the match has been played, and I told the lads that. You just have to give that bit extra against the big sides, and what the lads pulled off was no accident.
"Still, we mustn't get carried away, it's just one match. But we needed to persuade ourselves that we could be an excellent side. It was great to see the lads enjoy themselves and play good football."
Lille travel to Guingamp in their next match on Saturday.