Garbine Muguruza saw off Svetlana Kuznetsova 7-6(0) 6-2 in a rain-disrupted battle of former champions to reach the second round of the French Open on Tuesday.
The Spanish third seed, who lifted the Suzanne-Lenglen Cup in 2016, dropped serve twice in the opening set but easily prevailed in the tiebreak.
She broke early in the second set and this time did not let her guard down against 2009 champion Kuznetsova, who is 43rd in the WTA rankings after returning to the tour only in March following a wrist injury.
The Russian saved a first match point with a passing shot, Muguruza sent a backhand long on the second, but Kuznetsova bowed out after sending a forehand way too long on the third.
Muguruza next faces French wildcard Fiona Ferro.
In other early action on Tuesday, third-seed Marin Cilic defeated unseeded Australian James Duckworth in straight sets in rainy conditions to progress to the second round.
โItโs not often we play in the rain, so it was a bit differentโฆ the balls were a little bit heavier, a little bit different, but thatโs the special thing about the French Open,โ Cilic told the Philippe Chatrier court after his win.
The French Open is the only Grand Slam not to have a roofed court.
Cilic, who reached his third major final in Melbourne this year, was pushed to seven games in the second and third sets, winning 6-3 7-5 7-6(4). Duckworth is ranked 1072 in the world.
The Croatian would become only the 11th man in the Open era to reach the final of all four Grand Slams if he progresses through to the last two of this yearโs Coupe des Mousquetaires.
Canadian teenage sensation Denis Shapovalov meanwhile hit 32 winners to collect his first main draw win at Roland Garros, defeating John Millman of Australia 7-5 6-4 6-2.