(CNN) His face was creased with worry as he trailed a pumped-up rival, but Rafael Nadal re-emerged after an overnight rain delay to blow away Diego Schwartzman at Roland Garros.
The 10-time champion lost the first set 6-4 to the impressive Argentine Wednesday, but returned under sunny skies Thursday to win the next three sets 6-3 6-2 6-2 to reach the French Open semifinals.
Spain's Nadal will next play another Argentine Juan Martin del Potro after the former US Open champion beat Marin Cilic 7-6 5-7 6-3 7-5.
Nadal, dubbed the "King of Clay" for his domination on the red dirt, had his back against the wall at 3-2 down in the second set Wednesday before the match was halted for rain.
"I felt that I was playing a little bit under more stress than usual, and he was able to take control of the point too many times," said Nadal.
The delay enabled Nadal to regroup and he turned the deficit into a 5-3 lead before a second stoppage ended play for the day.
Returning to Court Philippe Chatrier Thursday, Nadal quickly polished off the second set, and with it, effectively, Schwartzman's challenge.
READ: Simona Halep reaches second French Open final
READ: Why Rafael Nadal is so dominant on clay
The faces of Roland Garros 2018
The 2018 French Open will take place from May 21-June 10 on the clay courts of Roland Garros in Paris.
Serena Williams turned heads in a black catsuit in her first-round match at Roland Garros, saying it made her feel like a "warrior princess." She also said it helped with ongoing blood clots following the birth of her daughter last year.
Rafa Nadal is favorite to take the men's singles title, which would be his 11th grand slam victory on the clay.
Serena Williams is playing her first grand slam for 16 months after maternity leave and is bidding for a fourth French Open crown and a record-equaling 24th major title, including both pre and Open era events.
Novak Djokovic hasn't won a grand slam title since 2016 and has slipped to No. 22 in the world, but he enters the French Open on a good run of form.
Young German Alexander Zverev is touted as the future of tennis but has struggled at grand slams so far in his career, his best result being the fourth round.
Andy Murray continues his recovery from hip surgery and won't be at Roland Garros -- a tournament he finished runner-up at in 2016.
Maria Sharapova is a two-time French Open champion but has missed the last two events at Roland Garros after serving a ban for testing positive for the illegal substance meldonium.
Pauline Parmentier will be flying the flag for France in the women's draw having received a wild card entry for this year's competition. She reached the fourth round in 2014.
Pat Cash claimed his sole grand slam singles title at Wimbledon in 1987. He'll be giving CNN his insight as a former player throughout the French Open.
A year on from her return to tennis following a knife attack in her home, Petra Kvitova says she is living a "dream."
Yannick Noah is still the only French man to win the French Open, since the Open era began in 1968. Noah's triumph at Roland Garros came way back in 1983.
Juan Martin del Potro's lone major title was the US Open in 2009. However he's struggled with injury since beating Roger Federer in that 2009 US Open final, missing almost the entire 2010 season after undergoing surgery on his wrist.
After slipping outside the world's top 400, Del Potro returned to the top five in 2013 but another wrist injury meant more surgery and led him to miss the majority of the 2014 and 2015 season. But earlier this year Del Potro ended Federer's best ever start to a season to become the first Argentine to win a top-tier Masters series event when he was victorious at Indian Wells.
Serena Williams pulled out injured ahead of her much-anticipated fourth-round match against old rival Maria Sharapova.
World No. 72 Marco Cecchinato beat David Goffin to reach the French Open quarterfinals where he will play Novak Djokovic. Cecchinato described his win over Goffin as the "best moment" of his life. He shortly followed up with a new best moment as he beat Djokovic in four sets.
Diminutive Argentine Diego Schwartzman, who stands at 5 feet 7 inches tall, proved size isn't everything when he toppled 6-foot-8 Kevin Anderson to reach the quarterfinals.
World No.1 Simona Halep is bidding for a first grand slam title after three previous losing final appearances in majors.
'Better level'
Despite some spirited resistance, the 11th seed couldn't live with Nadal's new-found intensity and revamped strategy, and the 16-time grand slam champion sealed the victory for the loss of only four games with his fourth match point.
"I played more aggressive. I continued the level of intensity that I played after the first stop. And in my opinion, the match changed," Nadal said.
He added: "It was a very difficult match against a good friend and good player. For me it's always big emotions to win here."
READ: Why Rafael Nadal is all at sea during time off from tennis
Nadal's streak of 37 consecutive set wins at Roland Garros ended Wednesday, but with victory the 32-year-old became only the third player in the Open era (since 1968) to reach 11 semifinals in the same grand slam. Roger Federer (Wimbledon) and Jimmy Connors (US Open) are the others.
No player in history has won as many grand slam titles at a single tournament as Nadal has in Paris.
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Nadal won the French Open on his debut as a 19-year-old and came into this year's event with a 79-2 win-loss record at Roland Garros.