PARIS — Austria’s Dominic Thiem had reason to celebrate Saturday after weathering fierce wind, a one-hour rain delay and two squandered match points before defeating world No. 1 Novak Djokovic on Day 2 of their previously halted semifinal at Roland Garros.

Now comes the tough part: taking on 11-time French Open champion Rafael Nadal less than 24 hours later for what would be his first Grand Slam title.

Thiem displayed fierce resolve in defeating Djokovic, the game’s most relentless defender, 6-2, 3-6, 7-5, 5-7, 7-5, on the red clay of Court Philippe Chatrier, where the Serb hoisted the French Open trophy in 2016, one of the rare years that Nadal hasn’t since his initial triumph in 2005.

With the victory, Thiem set up a reprise of last year’s French Open final, in which he was thrashed by Nadal in straight sets.

But Thiem, 25, is a more seasoned competitor now, ranked fourth in the world. And though Djokovic holds a 28-26 career advantage over Nadal, Thiem may pose the bigger challenge at Roland Garros for the Spaniard, who is seeking an 18th major that would nudge him closer to Roger Federer’s record 20.

Nadal and Thiem have met 11 times on clay, with Nadal holding a 7-4 advantage. But they’re 2-2 on the surface over the past two years, and Thiem won their most recent clash, in April, in straight sets at Barcelona.

“To play Rafa here on this court is always the ultimate challenge, one of the toughest challenges sports in general give,” Thiem said. “I think it’s really important that I go into the match with the belief to win. That’s the most important thing.”

The Djokovic-Thiem semifinal began Friday, after Nadal’s straight-sets dismissal of Federer, under gusty, turbulent skies. Thiem handled the aggravating conditions better and became the first man to claim a set against Djokovic all tournament. The Austrian led 6-2, 3-6, 3-1 when tournament officials halted the match for the night.

Though Djokovic didn’t explicitly criticize French Open officials for not stopping the match earlier Friday or for starting it in the first place, he made his displeasure clear in his post-match interview.

After congratulating Thiem on the victory, calling him “one of the best players in the world,” Djokovic said Friday’s weather was among the worst he had experienced as a pro.

“Obviously when you’re playing in hurricane kind of conditions, you know, it’s hard to perform your best,” said Djokovic, who had been playing nearly flawless tennis before facing Thiem and appeared to be on course for a collision with Nadal in the final. “It’s really just kind of surviving in these kind of conditions and trying to hold your serve and play one ball more than your opponent in the court.”

Asked whether he felt tennis should have a “wind rule,” a maximum wind speed in which matches could be contested, Djokovic said: “What I was explained yesterday on the court in the first set when I asked the supervisor, he came on the court and he said, ‘As long as there are no flying objects coming to the court, we’re good.’ I didn’t know that [an] umbrella is not a flying object, which flew in in the first game of the match, but that’s their decision. I guess they know tennis better.”

The weather was still unsettled when play resumed Saturday at noon — windy and cool, though less turbulent than Friday.

Thiem declared his resolve at the outset, saving break point on the 23rd stroke of a rally. Djokovic, 32, broke back and kept Thiem on his toes by attacking the net more often than he typically does.

Despite the wind, the quality of play was exceedingly high, featuring long rallies and a delicious variety of slice backhands, deft drop-shots and line-skimming passing shots.

After the Austrian seized a two-sets-to-one lead, Djokovic leveled the match in a fourth set littered with service breaks to force a fifth-set decider.

Thiem raced to a 4-1 lead, but a hard rain fell, sending players to the locker room while groundskeepers scurried to cover the court.

Djokovic returned reinvigorated from the hour-long break, making foray after foray to the net.

Thiem served for the match at 5-3 but flubbed successive backhands to lose his serve and give Djokovic new life. The Serb’s rally was short-lived, undone by his own spasm of errors.

Because of the rain that wreaked havoc on the tournament’s second week, Nadal enters Sunday’s final having played Tuesday and Friday, making the final his third match in six days.

For Thiem, by contrast, the final will be his fourth time on court in as many days.

But he didn’t quibble, noting that scheduling logjams are common in tennis.

“I’m not going to be tired,” Thiem insisted. “It’s all going to come after the tournament.

“So I’m ready to leave all or everything what I have out on the court tomorrow.”

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