Gael Monfils believes he was lucky to avoid serious injury after kicking an on-court clock, which fell at the US Open.

The entertaining Frenchman claimed a 6-4 6-2 7-6 (7-5) win over Gilles Muller in the first round on Monday.

But not before a bizarre incident on court 17, where Monfils was fortunate not to be hurt after kicking the clock trying to chase down a Muller overhead.

As the 10th seed retrieved his dropped racquet, the clock fell, and Monfils considered himself lucky to escape largely unscathed.

"When you are in the moment you don't feel really anything. Just jump. I saw it was a wall, but it was quite lucky," Monfils said afterwards.

"I was surprised [it fell], because it hurt me a little bit. You know, could be pretty bad. Could have fallen on my ankle or calf and could be more than that."

Monfils managed to advance despite the incident, setting up a second-round clash with Czech Jan Satral.