Jo Wilfried-Tsonga has expressed his relief at beating Philipp Kohlschreiber following a tough second-round match at the Monte Carlo Masters.

The French world number 12 was made to work against the German on Tuesday before eventually coming through in three sets.

"I was tired so it was a bit complicated for me," Tsonga is quoted as saying by the ATP's official website. "Fortunately I had an early break in the first set and I was able to hold my serve, but I knew it was going to be tough.

"Then I had this letdown in the second set. I was able to hang in there in the third set, and he ended up letting it go. It's maybe because I practised too much or I didn't manage the amount of effort I made."

Tsonga will now play either Roberto Bautista-Agut or 10th seed Fabio Fognini for a place in the quarter-finals.