CINCINNATI (AFP) — Carlos Alcaraz beat the heat and humidity of a Midwest summer as the world No. 2 advanced to the fourth round of the ATP and WTA Cincinnati Open on Tuesday.

The Spaniard moved through hours before an evening rainstorm and lightning spoiled the nighttime scenario, leaving men’s and women’s third seeds stranded in third-round matches.

Alexander Zverev was set to serve for the match against Brandon Nakashima, leading the American 6-4, 5-4 when the match was forced off the court by the threat of lightning.

It was a similar situation for American Jessica Pegula, fighting back against Pole Magda Linette, who won the first set 7-6 (7/5), before last year’s finalist claimed the second 6-3.

Toronto champion Ben Shelton never got on court against Roberto Bautista Agut due to rainstorm conditions that forced officials to call it a night early.

Second seed Alcaraz kept his exposure to a minimum in 32 Celsius conditions, taking an efficient 95 minutes to dispatch Serb Hamad Medjedovic 6-4, 6-4, for his 50th match win of the year.

“Medjedovic doesn’t like to run that much, so I tried to move him around as much as possible,” Alcaraz said. “But it was difficult with the ball flying so much and his shots coming so fast. I tried to defend in a good way.”

Alcaraz has been on a tear in 2025 as he chases Jannik Sinner in the ATP rankings, and now owns 13 straight victories at the Masters 1000 level.

He will play for the quarterfinals against Luca Nardi after the Italian defeated Jakob Mensik 6-2, 2-1 with the Czech retiring after 42 minutes.

Five-time Grand Slam winner Alcaraz, who is preparing for the approaching US Open start, added: “I was really happy to get the win in a very difficult match.”

“The season is very long and in at least half of your matches you don’t feel that good (physically).”

“But you have to stay positive and play your best tennis on the day. I’m proud of that. It’s a goal of the season.”

Toronto finalist Karen Khachanov, earned a 6-3, 6-3 win over Jenson Brooksby.

Francisco Comesano and Reilly Opelka both felt the heat of their mid-day match, which was interrupted for 45 minutes by rain, as the Argentine limped to a 6-7 (4/7), 6-4, 7-5 win while saving three match points.

Comesano needed a medical time out midway through the second set, but came back out to continue what turned into a fight of nearly three hours against the American.

Opelka called for the doctor just moments from his eventual loss, complaining of dizziness and high blood pressure after being broken for 5-6 in the final set.

After a quick consultation at his chair, Opelka was back on court to weakly scoop a return into the net on his opponent’s second match point.

The 71st-ranked South American will face ninth seed Andrey Rublev, who beat Australian Alexei Popyrin 6-7 (5/7), 7-6 (7/5), 7-5.

Opelka, noted for his big serve, fired 27 aces but also committed nearly 60 unforced errors. Comesano broke on four of his 13 chances.

He is the first Argentine into the Cincy round of 16 since Diego Schwartzman in 2022.

In the WTA draw, second seed Coco Gauff eased into the fourth round when opponent Dayana Yastremska withdrew before their Tuesday match.

The American, who won the 2023 Cincinnati title and followed up with a US Open crown, will await an opponent from former Roland Garros champion Jelena Ostapenko and Italian Lucia Bronzetti.

Yastremska was unable to play due to illness, the WTA said.