Japan's Kei Nishikori advanced to the French Open's round of 16 on the strength of a straight-sets victory over France's Gilles Simon on Friday.

Nishikori, the 19th seed, needed just 2 hours, 1 minute to dispatch Simon 6-3, 6-1, 6-3. Nishikori dominated at the net and with his returns, while winning 76 percent of the 60 points played off his first serve.

"He attacked well," Nishikori said of Simon, the third-straight French opponent he has faced here. "He's the kind of opponent that you can't beat unless you attack, so I told myself all week to be aggressive."

"This is the best match I've played all week. Now I want to make some adjustments ahead of my next match," he added.

Earlier, Japan's Naomi Osaka's bid to reach the fourth round at Roland Garros died in a straight-sets defeat to her American nemesis Madison Keys.

Keys, the 13th seed, came from 4-1 down in the second-set tiebreak to beat 21st seed Osaka 6-1, 7-6(7) in 1 hour, 21 minutes. Osaka had trouble with her serve at the start of the match, winning just three of the 11 points played on her first serve.

In the decisive tiebreak, Osaka twice had set point, but finally gave away the match with a double fault.

Osaka is now 0-3 in her career against Keys, with one of those losses a crushing third-round defeat at the 2016 U.S. Open. In that match, Osaka was one game from victory but blew a 5-1, third-set lead.