(Photo credit: Danielle Parhizkaran-USA TODAY Sports)
World No. 10 Alexander Zverev of Germany defeated unseeded Pavel Kotov of Russia 7-6 (5), 4-6, 6-1 on Saturday to advance to the quarterfinals of the Chengdu Open in Chengdu, China.
The top seed in the tournament, Zverev survived a marathon match of two hours and 26 minutes by winning on return points at a 36-percent rate (37 of 102) to 25 percent (20 of 80) for Kotov.
No. 2 seed Lorenzo Musetti of Italy also advanced by defeating Australia's Philip Sekulic 7-6 (3), 6-7 (4), 6-0.
Other winners included Grigor Dimitrov (6-3, 6-4 vs. Juan Pablo Varillas), Arthur Rinderknech (7-6 (2), 6-4 vs. Marcos Giron) and Miomir Kecmanovic (6-2, 6-4 vs. Corentin Moutet).
Great Britain's Cameron Norrie topped Australia's Marc Polmans 6-0, 6-3 to reach the Zhuhai Championships quarterfinals.
Ranked No. 17 in the ATP and seeded second in the tournament, Norrie coasted in 77 minutes by recording five aces and converting 75 percent (33 of 44) on service points.
Also on Saturday, Sebastian Korda defeated France's Alexandre Muller (6-1, 2-6, 6-3), Tomas Martin Etcheverry of Argentina upended the Czech Republic's Dalibor Svrcina (6-2, 6-3), and Russia's Aslan Karatsev edged Great Britain's Andy Murray (4-6, 6-3, 6-2).
--Field Level Media