Rafael Nadal and Simona Halep needed strong French Open showings to hold onto their top rankings. They did just that, becoming the first pair of ATP and WTA No 1s to both win the title at Roland Garros since Jim Courier and Monica Seles in 1992.
Nadal sits barely ahead of No. 2 Roger Federer on Monday, with a 100-point lead of 8,770 to 8,670.
They would have switched places if the Spaniard had failed to win his record-extending 11th championship Sunday.
"Today is all about Roland Garros," Nadal said after defeating Dominic Thiem 6-4, 6-3, 6-2 in Sunday's final. "I don't think about the rankings at all today, no?"
Alexander Zverev is No. 3, nearly 3,000 rankings points further back.
Juan Martin del Potro jumped two spots to No. 4 by reaching his first French Open semifinal in nine years, and Thiem rose one place to No. 7 by reaching his first Grand Slam final.
Marco Cecchinato made the biggest move in the ATP top 100, going up 45 spots to No. 27 — putting him in line for a Wimbledon seeding next month — after reaching the semifinals. At No. 72, he was the lowest-ranked semifinalist in 19 years.
The 25-year-old Italian had never won a Grand Slam match before this French Open, but he beat Novak Djokovic in the quarterfinals after also eliminating players seeded No. 8 and 10.
Halep, Caroline Wozniacki and Garbine Muguruza remained the WTA's top three, but French Open runner-up Sloane Stephens went from No. 10 to a career-high No. 4.
Madison Keys, who lost to Stephens in the semifinals, is now No. 10 after entering the tournament at No. 13.
Last year's champion in Paris, Jelena Ostapenko, dropped from No. 5 to No. 12 with a first-round exit this time. She was the first reigning women's champion to lose her opening match at the French Open since 2004.
Halep, who first grabbed the top ranking last October, could have been overtaken by five women if she didn't at least get to the semifinals at Roland Garros. But Halep not only made it to the semifinals, she beat 2017 U.S. Open champion Stephens 3-6, 6-4, 6-1 in the title match Saturday for her first Grand Slam trophy after three losses in major finals.
"The fact that I could be No. 1 in the world last year gave me confidence and gave me, like, a little bit of relief, because I touched something, something big, something huge," Halep said, "and I just had in my mind to win a Grand Slam after that."