By Ravi Ubha, CNN

(CNN) -- Serena Williams made a successful return to grand slam tennis Tuesday, beating Kristyna Pliskova 7-6 (7-4) 6-4 at the French Open.

Another former champion coming back to Roland Garros, Maria Sharapova, also advanced as did perennial men's winner Rafael Nadal as early rain in Paris gave way to sunshine.

Nadal, however, suffered one of his sternest opening tests at the tournament he has won a record 10 times and was forced to save four set points in a thrilling third-set tiebreak against Simone Bolelli.

Williams, who gave birth in September, hadn't featured at a major since winning the 2017 Australian Open while in the early stages of pregnancy.

Her return to tennis came earlier this year but she entered the French Open on a two-match losing streak and with no clay matches under her belt.

As a result of her inactivity on the tour, the American's ranking has slumped to 451st.

Nonetheless her coach Patrick Mouratoglou -- never one to set the bar low -- thinks that the 36-year-old can still land a fourth French Open title despite the dearth of matches and a tough draw.

If she succeeds, Williams would tie Margaret Court for the all-time record in majors with 24.

Despite some rust, Williams served brilliantly against Pliskova -- the twin sister of 2016 US Open finalist Karolina Pliskova -- and reversed a 3-0 deficit in the tiebreak. Mouratoglou and husband Alexis Ohanian cheered her on from the stands on Philippe-Chatrier court.

Williams recovered from a break deficit in the second set and saved three break chances in the final game.

Close finish for Sharapova

Deprived of a wildcard last year in the aftermath of a drug suspension, Sharapova earned a seeding this year but had to overturn a late deficit to defeat Dutch qualifier Richel Hogenkamp 6-1 4-6 6-3 on Court Suzanne Lenglen.

The two-time champion was breezing to victory at a set and 3-1 up, before her level dipped and Hogenkamp's elevated. Sharapova trailed 3-0 in the third and had to fend off two break points at 2-3 against the world No. 133.

Nadal was pushed by Italian lucky-loser Bolelli in the completion of their opener suspended by rain Monday but advanced 6-4 6-3 7-6 (11-9).

At nearly three hours, it was Nadal's second-longest first-round match at the French Open, behind his four-hour dual against John Isner in 2011.

The French Open is the lone grand slam without a roof and that isn't expected to change until 2020.

Garbine Muguruza shook off a rain delay to beat Svetlana Kuznetsova 7-6 (7-0) 6-2 in a clash of past French Open winners.