Naomi Osaka dug herself out of a hole at the French Open and kept her bid alive for a third consecutive Grand Slam title.

The opening set was only the second time in 13 major tournaments that the top-ranked Osaka has been on the losing end of a 6-0 score. The first was at Wimbledon in 2017.

Lacking accuracy early on the chilly Court Philippe Chatrier, Osaka donned a long-sleeve shirt for the second set and then broke Schmiedlova to love and served four aces in winning the first three games.

Schmiedlova and Osaka traded second-set breaks to get to the tiebreaker, where the Japanese player excelled.

The third set went quickly.

In keeping with the trend of the top women's players losing a set in their first-round matches at the French Open, defending champion Simona Halep overcame a mid-match lapse in a 6-2, 3-6, 6-1 win over 47th-ranked Ajla Tomljanovic.

"I need to be calm. Just focused on my game. Not thinking about my opponents and not thinking about the result," said Halep, who was a runner-up twice in Paris before earning the trophy in 2018.

Another French Open, another five-setter for No. 5 seed Alexander Zverev, who barely avoided blowing a big lead against John Millman.

Zverev struggled on a breezy and occasionally drizzly afternoon in the first round at Roland Garros before edging Millman 7-6 (4), 6-3, 2-6, 6-7 (5), 6-3 in 4 hours, 8 minutes.

A year ago in Paris, Zverev needed to win three consecutive matches that went the full five sets to get to his first Grand Slam quarterfinal.

He was shaky in the middle of the match against Millman, who upset Roger Federer at the 2018 U.S. Open.

Summed up Zverev, who had 57 winners and 73 unforced errors: "I'm through — and that's all that matters."

In his first Grand Slam match since fracturing his right kneecap, Juan Martin del Potro advanced to the second round of the French Open by beating 75th-ranked Nicolas Jarry 3-6, 6-2, 6-1, 6-4 through wind and bits of rain.

Del Potro, the 2009 U.S. Open champion and the runner-up there last year, started poorly in chilly conditions on Court Suzanne Lenglen. He was broken in his first service game by a forehand volley from Jarry at the net.

The Argentine, ranked No. 9, then took control, saving a break point in the second set and another in the fourth before serving out the win.

The frequently-injured del Potro was a semifinalist at Roland Garros last year.