Paris - Japan's Kei Nishikori saw off the challenge of French youngster Maxime Janvier to book his spot in the second round at Roland Garros on Sunday.
The 19th seed had to work hard to get past the plucky 21-year-old wildcard, but was always the stronger player in a 7-6 (7/0), 6-4, 6-3 victory on Court One.
Nishikori has risen back up the rankings after a strong clay-court season, which included a final loss to Rafael Nadal in Monte Carlo, having missed the early months of the campaign with right wrist injury.
The world number 21, who reached the French Open quarter-finals in 2015 and 2017, will next take on either home hope Benoit Paire or Spaniard Roberto Carballes Baena.
Janvier started brightly, with Nishikori having to stave off five break points in the fifth game as the opening set went to a tie-break.
But the former world number four raced through the breaker without dropping a point as Janvier appeared to feel the pressure.
From then on Nishikori was always in control, although he did have to save two break points to serve out the second set, before easing through the third.
Results from day one of the French Open at Roland Garros on Sunday (x denotes seeding):
Gael Monfils (FRA x32) bt Elliot Benchetrit (FRA) 3-6, 6-1, 6-2, 6-1
Grigor Dimitrov (BUL x4) bt Mohamed Safwat (EGY) 6-1, 6-4, 7-6 (7/1)
Damir Dzumhur (BIH x26) bt Denis Kudla (USA) 6-4, 6-2, 6-2
Radu Albot (MDA) bt Gregoire Barrere (FRA) 4-6, 0-6, 7-5, 6-1, 6-2
Ekaterina Makarova (RUS) bt Zheng Saisai (CHN) 6-4, 6-1
Barbora Strycova (CZE x26) bt Kurumi Nara (JPN) 1-6, 6-3, 6-4
Jennifer Brady (USA) bt Amandine Hesse (FRA) 6-1, 6-1
Petra Martic (CRO) bt Wang Yafan (CHN) 6-2, 6-3
Elina Svitolina (UKR x4) bt Ajla Tomljanovic (AUS) 7-5, 6-3
Anett Kontaveit (EST x25) bt Madison Brengle (USA) 6-1, 4-6, 6-2
Sloane Stephens (USA x10) bt Arantxa Rus (NED) 6-2, 6-0