World No 1 Aryna Sabalenka's preparations for her US Open title defence suffered a setback as she suffered a shock defeat to Sara Bejlek at the Cincinnati Open.

Czech Bejlek claimed the biggest win of her career with a 7-6(7) 6-4 victory over Sabalenka in the round of 16, rallying from 5-1 down in a first-set tiebreak and 4-1 behind inthe second set to secure her first win over a top 10 opponent.

The 20-year-old wrapped up the contest in about two hours and will next face Madison Keys in the quarter-finals.

Sabalenka's defeat means Elena Rybakina can replace her at the top of the rankings by reaching the Cincinnati final.

In the men's draw, American Tommy Paul battled back for a 4-6 7-6(6) 6-4 win over top seed Alexander Zverev to reach the last eight in Cincinnati for the first time.

World No 3 Zverev took the first set and trailed 3-4 in the second `before the match was suspended due to rain. Paul emerged from the nearly 90-minute delay looking the sharper player, saving a match point before levelling the contest as Zverev struggled to find his rhythm.

The German took a 4-2 lead in the third set but Paul dug his heels in to take control of the match, rallying to win four straight games in a stunning comeback. Zverev's 14 aces were accompanied by nine double faults, with his service game looking shaky at times after he was called for a foot fault in the third set.

Paul will next play Flavio Cobolli after the Italian earlier defeated Spain's Rafael Jodar 4-6 7-6(3) 6-3.

Reuters