Carlos Alcaraz was halted by rain on the brink of victory Thursday while defending women's champion Coco Gauff crashed out in her first match at the ATP and WTA Cincinnati Open.
Spaniard Alcaraz, the reigning Wimbledon and French Open champion, led France's Gael Monfils 6-4, 6-6 (1/3) when rain halted play at the last major tuneup for the US Open, which starts on August 26.
Top seed Alcaraz, who lost to Novak Djokovic in last year's Cincinnati final, took a silver medal at the Paris Olympics, also dropping that final to Djokovic.
Alcaraz is back on hardcourt for the first time since winning at Miami. He skipped last week's ATP Montreal Masters.
Gauff was eliminated earlier in a 6-4, 2-6, 6-4 upset loss to Kazakh spoiler Yulia Putintseva.
A disappointed Gauff will go back to the drawing board before defending her US Open crown.
Putintseva, ranked 34th, has made a recent habit of upsets, knocking off top-ranked Iga Swiatek barely a month ago at Wimbledon.
"I'm really proud of myself," said Putintseva. "These courts are so fast, you have to just play on instinct. That's what I did."
Gauff became Cincinnati's youngest champion a year ago at age 19 and carried that success into her first Grand Slam triumph at the US Open.
"I have to work on consistency. overall," Gauff said. "I'm making a lot of unforced errors, especially when I was up 4-2 (in the third set)," Gauff said. "Most of the points (Putintseva won) were off (my) errors.
"She's tricky to play, mixes up the ball and likes drop shots, She makes you earn the match."
Putintseva will next face Spain's Paula Badosa, who defeated Anna Kalinskaya 6-3, 6-2.
Third seed Aryna Sabalenka polished her opening-match record at the event by defeating Italy's Elisabetta Cocciaretto 6-3, 6-4.
Sabalenka missed Wimbledon and the Paris Olympics with a right shoulder injury but feels well.
"I'm happy with my level in the tough moments," Sabalenka said. "Elisabetta is a difficult opponent. She fought to the last point."
ZVEREZ ADVANCES
Men's third seed Alexander Zverev, the 2021 champion from Germany, won his ATP-leading 50th match this season. The German dispatched Karen Khachanov 6-3, 6-2 in a repeat of his Tokyo Olympic final win.
Zverev, feeling poorly last week in Montreal, said his form is much improved.
"I felt well on court. If you feel good in training it's easier to bring it to the match," he said. "I just hope my form can get better. I'm happy I got the win today."
Spain's Pablo Carreno Busta lined up the German's next opponent after defeating Australian Max Purcell 6-3, 6-3.
Briton Jack Draper accounted for ninth seed Stefanos Tsitsipas, who lost 3-6, 6-4, 7-5. The Greek served for the match leading 5-4 in the third set, but Draper won 12 of the last 14 points to turn the situation on its head.
Holger Rune defeated Portugal's top player Nuno Borges 6-3, 7-6 (10/8).
Fifth seed Hubert Hurkacz, who made a surprise comeback from July knee surgery by reaching last week's Montreal quarterfinals, won his opener over Yoshihito Nishioka 3-6, 7-6 (7/4), 6-1.
He next faces Italian Flavio Cobolli, who advanced when compatriot Luca Darderi retired trailing 7-6 (7/4), 3-1 with apparent illness.
In the WTA draw, Elena Rybakina was thwarted in her first match since Wimbledon, going down 3-6, 7-6 (7/3), 6-4 as Canadian Leylah Fernandez saved two match points in an upset of the fourth seed.
Rybakina, who missed the Paris Games with acute bronchitis, suffered with 17 double faults – including on match points. Even 20 aces could not save her afternoon.
Elina Svitolina, a semifinalist here nine years ago, saw off Spaniard Jessica Bouzas Maneiro 6-4, 6-1 to next take on Sabalenka.
Sabalenka has won their last two matches, including a Roland Garros quarterfinal in 2023 and a three-setter in Rome three months ago.
Newly minted Armenian Elina Avanesyan stunned eighth seed Jelena Ostapenko with a 2-6, 6-2, 6-2 fightback.