Roger Federer has admitted that he struggled to beat Nicolas Mahut in his third-round win at the French Open.
The world number three defeated the spirited Frenchman in four sets in Paris on Friday to book his place in the last 16.
"I struggled a little bit, but overall obviously I'm happy I came through," Federer told BBC Sport.
The Swiss will now meet Belgium's David Goffin for a place in the quarter-finals.
