Top seeds Aryna Sabalenka and Alexander Zverev crashed out of the Cincinnati Masters in a matter of hours on a rainy Wednesday of fourth-round action. American Tommy Paul saved a match point on the way to a 4-6, 7-6 (8/6), 6-4 upset of Germany’s Zverev. But the biggest shock came on the women’s side where Czech Sara Bejlek, ranked 35th, stunned world number one Sabalenka 7-6 (9/7), 6-4 in a gritty match that finished up shortly after the clock ticked past midnight into Thursday morning.

Former champion Sabalenka led by a break in the opening set and was up 5-1 in the tiebreaker before Bejlek roared back to pocket the set in 65 minutes.

Bejlek broke the Belarusian three times in the second set, rallying from 4-1 down and securing the win with a love game capped by an ace.

“I lost my words — it feels incredible,” Bejlek said after her first win over a top-10 player.

“I was playing what I was feeling and not really thinking. I was trying not to be nervous and just play. I believed in myself no matter what.”

Bejlek, who won the Abu Dhabi hard court title in February as a qualifier, booked a quarter-final clash with American Madison Keys.

It was yet another setback for Sabalenka as the start of the US Open looms on August 30.

The four-time Grand Slam champion was ousted in the fourth round of the Toronto Masters last week, having lost in the same round at Wimbledon and in the quarter-finals at Roland Garros.

Zverev’s match was interrupted by rain for 90 minutes in the seventh game of the second set and had two more five-minute pauses as drops were dried from the court.