Last updated on .From the section Tennis

Muguruza finished the match with an ace

French Open Venue: Roland Garros, Paris Dates: 28 May- 11 June Coverage: Listen to live radio commentary and follow text coverage of selected matches on BBC Radio 5 live sports extra and online.

Defending champion Garbine Muguruza reached the fourth round of the French Open with a 7-5 6-2 win over Kazakhstan's Yulia Putintseva.

The Spaniard has had a patchy year so far and is seeking to regain the form that enabled her to secure her first Grand Slam title in Paris last year.

She will face France's 13th seed Kristina Mladenovic in the last 16.

Seven-time Grand Slam champion Venus Williams, 36, joined them with an impressive win against Elise Mertens.

Fourth seed Muguruza, 23, took a tight first set that featured seven breaks of serve but improved in the second set to see off Putintseva, a surprise quarter-finalist at Roland Garros last year.

"I'm happy I went out there without any kind of fear," said Muguruza.

"I wanted the match. I tried to just do what I had to do and keep that during the whole match.

"The more matches I play and the tougher victories gives you self-confidence, a successful feeling out there."

Mladenovic, 24, reached the last 16 at Roland Garros for the first time with a remarkable comeback win against American Shelby Rogers.

The Frenchwoman won 7-5 4-6 8-6 against Rogers, who reached the quarter-finals last year, after trailing 5-2 in the deciding set.

Venus to make more history?

Venus Williams has won Wimbledon five times (2000, 2001, 2005, 2007 and 2008) and the US Open twice (2000 and 2001). But she is yet to win Roland Garros after losing in the 2002 final...

Williams is making an Open Era record 20th appearance at Roland Garros, having missed just one tournament in Paris since her debut appearance in 1997.

And, on the evidence of a clinical win against Belgium's Mertens, the American is a serious contender to win her first title on the French clay.

She swept past her unseeded opponent in one hour and two minutes to win 6-3 6-1.

In the last 16, Williams will play Switzerland's 30th seed Timea Bacsinszky, who defeated unseeded Tunisian Ons Jabeur.

Elsewhere, Denmark's Caroline Wozniacki, the 11th seed, will finish her match against 18-year-old unseeded American Cici Bellis on Saturday. Wozniacki took the first set 6-2 with Bellis leading 5-2 in the second before rain caused an early end to Friday's play.

Russia's Svetlana Kuznetsova, the 2009 champion, moved into the last 16 with a hard-fought three-set win against China's Zhang Shuai.

The eighth seed needed more than three hours to eventually see off 32nd seed Zhang in a 7-6 (7-5) 4-6 7-5 win.