Paris - Rafael Nadal survived a mini-crisis to rack up his 80th win at Roland Garros on Tuesday as the 10-time champion defeated Italian lucky loser Simone Bolelli 6-4, 6-3, 7-6 (11/9) to reach the second round.
Nadal had to save four set points in the tiebreaker before wrapping a victory which preceded the widely-awaited return to Grand Slam tennis of 23-time major winner Serena Williams.
World No 1 Nadal had been two sets up but 0-3 down in the third when rain caused the tie to be suspended late on Monday.
He quickly levelled at 3-3 on Tuesday, saved four break points in the eighth game before saving four set points.
Nadal eventually claimed the match on a third match point when Bolelli dumped a forehand into the net.
The top seeded Nadal, bidding for an 11th title in Paris and his 17th major, next faces Argentina's Guido Pella for a place in the last 32.
"I really suffered today but it was a good test," said Nadal who had been in danger of dropping his first set at Roland Garros since his 2015 quarter-final loss to Novak Djokovic.
"It was very difficult. Simone is a very good player and he had lots of chances and was very agrressive.
"But I am happy to have won here on this court, the most important of my career."
Williams returns to Grand Slam tennis for the first time since the 2017 Australian Open where she won a 23rd major while also being two months pregnant.
The 36-year-old's return comes with the great American ranked at a lowly 451, a consequence of her lengthy absence from the tour after giving birth to her daughter in September.
Williams has played just four matches in 2018, the last of which was a first-round exit to Naomi Osaka in Miami.
Three of her Slam titles have come in Paris - in 2002, 2013 and 2015 - and longtime coach Patrick Mouratoglou has no doubt that Williams is capable of adding a fourth.
"Can she do it? Serena can achieve anything - after being her coach for six years, I'm even more sure of that statement," said the Frenchman.
Williams starts her 16th Roland Garros against Czech world No 70 Kristyna Pliskova who has never won a match at the tournament in four visits.
After getting rained off the schedule on Monday night, two-time champion Maria Sharapova also makes a comeback to the tournament after missing the 2016 and 2017 editions.
Sharapova was refused a wild card last year by French Open organisers uncomfortable with being seen to hand out a free pass to a player who had just completed a 15-month doping ban.
Five-time major winner Sharapova faces Dutch qualifier Richel Hogenkamp, ranked at 133, on Court Suzanne Lenglen.
Third seed Marin Cilic reached the second round with a 6-3, 7-5, 7-6 (7/4) win over Australia's James Duckworth.
Wimbledon and Australian Open runner-up Cilic, 29, fired 47 winners and 13 aces past the 1 072th-ranked Duckworth who was playing his first match since the 2017 Australian Open.
Since that time, the 26-year-old has been battling a foot injury which required surgery in January 2017.
Canadian teenager Denis Shapovalov eased to a 7-5, 6-4, 6-2 victory over Australian John Millman in his first ever main-draw French Open match.
The 19-year-old, who lost in Roland Garros qualifying last year but is now the 24th seed, will next take on German world No 70 Maximilian Marterer for a place in the last 32.
"The last couple of weeks I've been playing unbelievable on this surface," said Shapovalov.
This year is the first time Shapovalov has been seeded at a major after his run to the Madrid Masters semi-finals earlier this month saw him become the youngest player to break into the world's top 30 since 2005.
Third seed and 2016 champion Garbine Muguruza defeated 2009 winner Svetlana Kuznetsova 7-6 (7/0), 6-2.
Spain's Muguruza next faces French wildcard Fiona Ferro, ranked 257, for a place in the last 32.
With the headlines dominated by the returns of Williams and Sharapova, world number one Simona Halep will begin her latest bid to win a maiden Slam very much under the radar.
The Romanian, who blew a set and 3-0 lead to lose the 2017 final to Jelena Ostapenko, faces Alison Riske, the 83rd-ranked American.
Results from day three of the French Open at Roland Garros on Tuesday (x denotes seeding):
Rafael Nadal (ESP x1) bt Simone Bolelli (ITA) 6-4, 6-3, 7-6 (11/9)
Guido Pella (ARG) bt Joao Sousa (POR) 6-2, 6-3, 6-4
Denis Shapovalov (CAN x24) bt John Millman (AUS) 7-5, 6-4, 6-2
Maximilian Marterer (GER) bt Ryan Harrison (USA) 6-1, 6-3, 7-5
Ruben Bemelmans (BEL) bt Yuki Bhambri (IND) 6-4, 6-4, 6-1
Jurgen Zopp (EST) bt Jack Sock (USA x14) 6-7 (4/7), 6-2, 4-6, 7-6 (7/5), 6-3
Thomas Fabbiano (ITA) bt Matthew Ebden (AUS) 6-4, 5-7, 6-2, 3-6, 6-2
Sergiy Stakhovsky (UKR) bt Feliciano Lopez (ESP x28) 6-2, 6-4, 6-2
Mischa Zverev (GER) bt Florian Mayer (GER) 6-2, 6-1, 7-6 (7/3)
Pablo Cuevas (URU) bt Aljaz Bedene (SLO) 6-4, 6-3, 6-2
Kevin Anderson (RSA x6) bt Paolo Lorenzi (ITA) 6-1, 6-2, 6-4
Marin Cilic (CRO x3) bt James Duckworth (AUS) 6-3, 7-5, 7-6 (7/4)
Hubert Hurkacz (POL) bt Tennys Sandgren (USA) 6-2, 6-2, 3-6, 6-3
Jan-Lennard Struff (GER) bt Evgeny Donskoy (RUS) 6-1, 6-3, 6-0
Steve Johnson (USA) bt Adrian Mannarino (FRA x25) 7-6 (7/1), 6-2, 6-2
Fabio Fognini (ITA x18) bt Pablo Andujar (ESP) 6-4, 6-2, 6-1
Elias Ymer (SWE) bt Dudi Sela (ISR) 7-6 (7/3), 6-3, 6-1
Marton Fucsovics (HUN) bt Vasek Pospisil (CAN) 6-3, 6-3, 7-6 (7/5)
Kyle Edmund (GBR x16) bt Alex De Minaur (AUS) 6-2, 6-4, 6-3
John Isner (USA x9) bt Noah Rubin (USA) 6-3, 7-6 (9/7), 7-6 (9/7)
Horacio Zeballos (ARG) bt Yuichi Sugita (JPN) 6-4, 6-7 (3/7), 6-4, 6-2
Juan Martin del Potro (ARG x5) bt Nicolas Mahut (FRA) 1-6, 6-1, 6-2, 6-4
Taylor Townsend (USA) bt Myrtille Georges (FRA) 6-4, 6-2
Bethanie Mattek-Sands (USA) bt Johanna Larsson (SWE) 6-4, 6-3
Daria Gavrilova (AUS x24) bt Sorana Cirstea (ROU) 4-6, 7-6 (7/4), 6-3
Elise Mertens (BEL x16) bt Varvara Lepchenko (USA) 6-7 (9/11), 7-6 (7/4), 6-0
Angelique Kerber (GER x12) bt Mona Barthel (GER) 6-2, 6-3
Ana Bogdan (ROU) bt Marketa Vondrousova (CZE) 6-3, 1-6, 6-4
Aliaksandra Sasnovich (BLR) bt Denisa Allertova (CZE) 6-4, 6-3
Kiki Bertens (NED x18) bt Aryna Sabalenka (BLR) 6-2, 6-1
Zhang Shuai (CHN x27) bt Kristna Kucova (SVK) 6-0, 7-5
Irina Camelia Begu (ROU) bt Anna Karolina Schmiedlova (SVK) 6-4, 5-7, 9-7
Peng Shuai (CHN) bt Aleksandra Krunic (SRB) 6-3, 6-4
Caroline Garcia (FRA x7) bt Duan Ying-Ying (CHN) 6-1, 6-0
Garbine Muguruza (ESP x3) bt Svetlana Kuznetsova (RUS) 7-6 (7/0), 6-2
Fiona Ferro (FRA) bt Carina Witthoeft (GER) 6-4, 6-2
Samantha Stosur (AUS) bt Yanina Wickmayer (BEL) 6-2, 6-4
Anastasia Pavlyuchenkova (RUS x30) bt Polona Hercog (SLO) 6-4, 7-6 (7/1)
Julia Goerges (GER x11) bt Dominika Cibulkova (SVK) 6-4, 5-7, 6-0
Alison Van Uytvanck (BEL) bt Isabelle Wallace (AUS) 6-1, 6-0
Serena Williams (USA) bt Kristyna Pliskova (CZE) 7-6 (7/4), 6-4
Ashleigh Barty (AUS x17) bt Natalia Vikhlyantseva (RUS) 6-3, 6-1
Maria Sharapova (RUS x28) bt Richel Hogenkamp (NED) 6-1, 4-6, 6-3