Rafael Nadal started his quest for a record-extending 13th French Open title with a straightforward 6-4 6-4 6-2 first-round win against Belarusian Egor Gerasimov.
The Spaniard, looking to equal Roger Federer's record of 20 Grand Slam men's singles titles, is used to slow starts at Roland Garros and this year's debut was no different.
On the revamped court Philippe Chatrier, whose roof stayed open throughout, Nadal converted all of his five break points to set up a meeting with American Mackenzie McDonald.
The second seed, who had complained about the new balls being too heavy, did not appear too bothered in front of some 200 fans, wrapping up the match with a service winner.
"I want to play matches with a positive attitude. It's a different Roland Garros with challenging weather conditions," said Nadal.
With his topspin having less of a devastating effect on the heavier clay, Nadal had to adapt and play more aggressively than usual, taking the ball earlier to unsettle his opponent - a tactic that worked perfectly.
He broke in the fifth game as he bagged the opening set in solid fashion, and he stole his opponent's serve again in the third game of the second.
With a mountain to climb after falling two sets behind and as blue skies ate away the dark clouds, Gerasimov broke for 2-0 in the third set.
Nadal quickly regained control, however, and levelled for 2-2, with Gerasimov twisting his ankle on the last point of the fourth game.
The physiotherapist taped the Belarusian's ankle and play resumed after a short interruption with Nadal breaking again for 3-2.
Gerasimov's challenge was fading as Nadal piled on the pressure to seal a routine win, moving a step closer to a potential semi-final with last year's runner-up Dominic Thiem.
Austria's Thiem showed no sign of a hangover from his US Open triumph as he began his Roland Garros campaign with an impressive 6-4 6-3 6-3 win over Marin Cilic.
Third seed Thiem, beaten by Nadal in the last two French Open finals, was handed a tough first round against the Croatian former US Open champion, but was straight into the groove under the roof on Court Phillipe Chatrier.
Cilic, who before Thiem's Flushing Meadows win this month was the most recent first-time Grand Slam champion courtesy of his New York title in 2014, made things difficult for Thiem with some aggressive tactics but faltered at crucial moments.
Thiem broke the Cilic serve at 4-4 in the first set and then came from 0-40 down to seal the opening set.
Using his powerful single-handed backhand to damaging effect on the heavy claycourt, Thiem dominated the second set.
The 27-year-old lapsed briefly to trail 0-2 in the third but switched on the afterburners to reel off five games in a row before 40th-ranked Cilic stopped the rot.
Thiem had to save a break point when he served at 5-3 and claimed his fourth win in four meetings with Cilic as the Croat netted a return off a second serve.
But Daniil Medvedev's miserable relationship with the French Open continued when the fourth seed was bundled out in the first round by Hungary's Marton Fucsovics late on Monday.
With the time nearing midnight on a near-deserted Court Suzanne Lenglen, Fucsovics completed a shock 6-4 7-6(3) 2-6 6-1 win in a match of brutal rallies and tetchy exchanges.
Medvedev, who has beaten Fucsovics in their previous three encounters, now has the unwanted statistic of losing in the first round at Roland Garros in four successive years.
The Russian's frustration boiled over at the end of the second set when, after losing a sensational rally to go down 3-6 in the tiebreak, he destroyed his racket frame and was given a penalty point that handed the set to Fucsovics.
To his credit the 24-year-old Medvedev regained his composure to dominate the third set.
But with the temperature dipping towards single digits and both players putting on extra layers of clothing to stay warm at changeovers it was Fucsovics who was re-energised.
He quickly built up a commanding lead in the fourth set as Medvedev's resolve ebbed away and earned his first career victory over a top-10 player when the Russian netted.
Felix Auger-Aliassime's main draw debut ended swiftly with a first-round exit as the Canadian was humbled 7-5 6-3 6-3 by Yoshihito Nishioka.
The 20-year-old, who is in his second senior appearance at Roland Garros after losing in qualifying in 2018, never found his range under threatening skies on Court Nine.
Nishioka dropped serve early in the first set before taking control of the rallies and benefiting from his 19th-seeded opponent's 58 unforced errors to set up a match against French wildcard Hugo Gaston.
The 14th seed Fabio Fognini, was also sent packing when he lost 7-5 3-6 7-6(1) 6-0 to Kazakhstan's Mikhail Kukushkin.
The Italian, who had surgery on both his ankles earlier this year, limped to his chair after the third set and called the physiotherapist.
The 33-year-old resumed play but apparently lost all interest in the contest, handing the remaining games to his opponent.
