Andy Murray says his hard-fought victory over Radek Stepanek at the French Open could be one of the biggest of his career.

The world number two completed his fightback to claim a 3-6 3-6 6-0 6-3 7-5 victory on Tuesday, with the match having been halted for poor light late on Monday.

"It could turn out to be one of the biggest wins of my career," Murray said. "It may not, but to get through that match, it was really, really important for me.

"And it easily could have gone the other way. When it is pretty much one set to stay in the tournament, you have to have as much energy, intensity as you can.

"You know, I'm glad that my team's right behind me in situations like that."

Murray struggled on serve in the early stages and was broken four times in the first two sets to leave world number 128 Stepanek, 37, eyeing a major upset at Roland Garros.

"I didn't start as well as I would have liked, for sure," added Murray. "Yesterday was a tricky day. And a few days before, getting ready for the tournament, because of the conditions and the rain, [there] was a good chance we maybe weren't going to play yesterday, either.

"Then you start off late, and you're aware that if it goes long that maybe you don't get the chance to finish. I maybe put a little bit of extra pressure on myself at the beginning, which maybe didn't help.

"And then because of the way the court's playing, it's extremely heavy. It's very difficult to push guys back. Players are hitting the ball relatively flat. It's not playing like a true clay court right now because of how heavy it is.

"He was stepping into the ball and coming forward, dictating a lot of points. I couldn't get the ball out of his strike zone at the beginning. Thankfully managed to turn that around, but it obviously wasn't the best start."

Murray will face French qualifier Mathias Bourgue in the second round.