Venus Williams reaches third round of French Open as Serena Williams watches

With her pregnant sister watching from the stands, Venus Williams overcame a sluggish start to beat Kurumi Nara of Japan 6-3, 6-1 and reach the third round of the French Open on Wednesday.

American Serena Williams, the owner of 23 Grand Slam singles titles, made a surprise appearance at Roland Garros as a spectator. Her baby is due in the fall and she plans to return to the tour in 2018. She sat in shade at Court Philippe Chatrier during older sister Venus' second-round match.

Venus Williams, the No. 10 seed and a runner-up in Paris in 2002, trailed 3-1 in the opening set before finding her form and winning seven consecutive games.

"I love being here and I love playing on this court," said the 36-year-old Williams, who is playing at Roland Garros for the 20th time, a record in the Open era. "You never stop learning and that's what I love about the game."

Williams will next face either Richel Hogenkamp of the Netherlands or Elise Mertens of Belgium.

"It's always a joy when you can control the match," Williams said after the 80-minute match. "It was a little bit tricky there, but, you know, just try to still control the match. That always feels good."

Williams spoke about Serena's presence as a spectator.

"Yeah, she said, 'Good job,' Venus said of the brief post-match conversation she had with Serena. "Yeah, she came in sometime during the match. I don't know exactly when.

"I'm sure she feels the excitement of being at a major and not having the pressure to play and prepare. Must be an interesting feeling to say the least. But she knows exactly what it's like out there, and she's had a lot of success here. If she stays here through the end, I would like that."

Meanwhile, Petra Kvitova's first tournament since she was injured in a December knife attack at her Czech Republic home came to an end.

The 15th-seeded Kvitova, a two-time Wimbledon champion, lost to American qualifier Bethanie Mattek-Sands 7-6 (5), 7-6 (5) after she double-faulted on match point.

Mattek-Sands, a doubles champion at Roland Garros two years ago, will next face 23rd-seeded Australian Samantha Stosur, who beat Kirsten Flipkens of Belgium 6-2, 7-6 (6).

Russian Ekaterina Makarova, who upset world No. 1 Angelique Kerber in the first round on Sunday, could not follow up on her stunning performance.

Makarova exited on Wednesday, losing to 42nd-ranked Lesya Tsurenko of Ukraine 6-2, 6-2 after making 27 unforced errors and dropping her serve five times.

Defending champion and No. 4 seed Garbine Muguruza of Spain held on to beat Anett Kontaveit Estonia 6-7 (4), 6-4, 6-2 to reach the third round.

American teenager CiCi Bellis upset 18th-seeded Kiki Bertens of the Netherlands 6-3, 7-6 (5). The 18-year-old Bellis is playing in her third career Grand Slam tournament and first in the French Open.