Jo-Wilfried Tsonga of France reached the quarterfinals of the 2015 French Open, beating No. 4 seed Tomas Berdych of Czech Republic in four sets, 6-3, 6-2, 6-7(5), 6-3. Tsonga, who is seeded 14th in this tournament, improved to 3 wins against 9 losses versus Berdych in their career head-to-head meetings. Berdych defeated Tsonga, 7-5, 6-2 in the quarterfinal round of the ATP World Tour Masters in Madrid, Spain, earlier this year.

"I'm feeling good. I'm playing good tennis. I'm solid. When I play my best tennis, I know I'm able to beat many guys,” Tsonga said via the tournament’s official website. “I always believed in me and try to be really consistent in my head. Sometimes your body is not right. Sometimes you don't have enough tennis. So you never know. I have people around me who stay positive for me, and they help me to never give up. That's why I'm happy today, because the confidence is back.”

Tsonga had more unforced errors, 41 to 35 and double-faults, 4-2 but the Frenchman, who was playing in front of a raucous home crowd, broke the Czech’s serve in six of 10 break opportunities. Tsonga advanced to the next round where he’ll face Japan’s Kei Nishikori, who beat Teymuraz Gabashvili, 6-3, 6-4, 6-2, in his own Round of 16 match.

“We haven’t played in a long time, maybe couple of years,” Nishikori said in the post-match news conference about his match-up with the Frenchman. “But he was injured and now he’s coming back very strong. He has a big serve, big forehand. He’s always dangerous.”

The 25-year-old Japanese holds a 4-1 win-loss career record against the 30-year-old Tsonga and won the last match-up, a 6-1, 4-6, 6-4 Round of 16 victory at the ATP World Tour Masters in Paris in earlier this year.

Berdych became the highest-seeded casualty in the fourth round, with Andy Murray, Roger Federer and Novak Djokovic -- seeded third to first -- all playing for a slot in the quarterfinal round.