Tries from Louis Picamoles and Yoann Huget put France 14-0 up quickly in the first half.
They ended the first period 16-0 in front before Wales made their comeback.
A try from Tomos Williams and two from George North was enough to turn it around for Gatland’s team.
Gatland spoke after the game an spoke about his side’s resilience.
He also mentioned George North’s first half mistake, but praised his players for their resilience.
“George North did alright today. He’ll be disappointed with the try where he was stepped defensively,” he said.
“The message at half-time was to just raise the tempo. As a team we’ve forgotten how to lose and they’ve probably forgotten how to win a bit.
“It’s nice to get out of jail 16-0 down and win the game so we’ll take it.
“Today our game management was poor but we found a way to win.
“It’s a big start for us. We’ve got an eight-day turnaround with Italy next week so we’re looking forward to the next few days.
“Everyone who’s won this championship in the last 10 years will recognise there’s games where you get a bit lucky. Like the Johnny Sexton drop-goal last year.
“We look back on times when we’ve won the Grand Slam and had a bit of luck. You need that to win the championship.”
North, who was excellent in the second half for Wales, also had his say.
“We spoke all week about chasing everything down. We didn’t have much luck in the first half but in the second half it was all hands on deck,” he said.
“I’m really happy. We made a few mistakes in the first half. The message at half-time was clear and it showed in the second half.”