Cincinnati – Novak Djokovic battled stomach issues and a slow start before dispatching Adrian Mannarino to reach the third round in Cincinnati on Wednesday, but third seed Alexander Zverev again crashed out prematurely.
The Wimbledon champion called for the doctor during the second set of his encounter with Mannarino but put aside his discomfort to progress with a 4-6, 6-2, 6-1 win over the Frenchman.
He will meet title-holder Grigor Dimitrov or Mischa Zverev for a place in the quarter-finals at the only Masters event missing from the Serb’s collection.
Marin Cilic, the 2016 champion, beat Romanian Marius Copil 6-7 (4/7), 6-4, 6-4, but Alexander Zverev was dumped out in a 5-7, 6-4, 7-5 upset by Robin Haase.
The German remains winless in four appearances at the pre-US Open tournament. His early exit comes a week after he lost in the Toronto quarter-finals to fellow youngster Stefanos Tsitsipas.
The 55th-ranked Haase clinched a surprise victory when Zverev fired a return long after losing serve six times.
“I think I played well. Today my returns I think were really, really good,” Haase said.
“I think the first serve he hit at me was 136 (mph), and I just hit it right back. I was good from my side.
“Nowadays against top 10, 20, maybe top 50 you have to be a little bit lucky.”
Zverev came into the event leading the ATP with 43 match wins this season, while it was a seventh career win over a top 10 player for Dutchman Haase.
In the women’s draw, defending US Open champion Sloane Stephens was untroubled on her way into the third round, defeating German qualifier Tatjana Maria 6-3, 6-2.
The third-ranked American, who lost the Montreal final to world number one Simona Halep last weekend, reached the semi-finals here a year ago before falling to the Romanian.
Aryna Sabalenka of Belarus continued her successful tournament debut, beating ninth seed Karolina Pliskova 2-6, 6-3, 7-5.
Australian 16th seed Ash Barty beat Estonian Kaia Kanepi 7-5, 6-3, while Gstaad champion Alize Cornet was crushed 6-2, 6-0 by Ekaterina Makarova.
Results from the ATP and WTA Cincinnati Masters tournament on Wednesday (x denotes seeding):
Milos Raonic (CAN) bt Malek Jaziri (TUN) 6-3, 7-5
Novak Djokovic (SRB x10) bt Adrian Mannarino (FRA) 4-6, 6-2, 6-1
Robin Haase (NED) bt Alexander Zverev (GER x3) 5-7, 6-4, 7-5
Marin Cilic (CRO x7) bt Marius Copil (ROU) 6-7 (4/7), 6-4, 6-4
Aryna Sabalenka (BLR) bt Karolna Plskov (CZE x9) 2-6, 6-3, 7-5
Elise Mertens (BEL x15) bt Rebecca Peterson (SWE) 3-6, 6-2, 7-6 (7/1)
Sloane Stephens (USA x3) bt Tatjana Maria (GER) 6-3, 6-2