Qualifier Tommy Paul recorded the biggest win of his career Wednesday, upsetting second-seeded Alexander Zverev of Germany 6-3, 6-4 in the second round of the Mexican Open at Acapulco.
Paul, a 22-year-old New Jersey native who is ranked 66th, never previously beat a player ranked in the world's top 10. Zverev, who reached the final in Acapulco last year, is No. 7.
Next up for Paul is a quarterfinal matchup with fifth-seeded John Isner, who beat Marcos Giron 6-3, 7-6 (4) in an all-U.S. showdown.
Also advancing to the quarterfinals were seventh-seeded Grigor Dimitrov of Bulgaria, Soonwoo Kwon of South Korea, Kyle Edmund of Great Britain and Taylor Fritz of the United States.
Dubai Duty Free Tennis Championships
Top-seeded Novak Djokovic of Serbia cruised to a 6-3, 6-1 win over Germany's Philipp Kohlschreiber in the second round at Dubai, United Arab Emirates.
Djokovic put just 55 percent of his first serves in play, but he never faced a break point. He is set for a quarterfinal meeting with seventh-seeded Russian Karen Khachanov, who dispatched Austrian qualifier Dennis Novak 6-3, 6-4.
Others winning second-round matches were second-seeded Stefanos Tsitsipas of Greece, third-seeded Gael Monfils of France, sixth-seeded Andrey Rublev of Russia, France's Richard Gasquet, Great Britain's Daniel Evans and Germany's Jan-Lennard Struff.
Chile Dove MenCare Open
Argentinian qualifier Renzo Olivo, ranked 297th in the world, upset seventh-seeded Uruguayan Pablo Cuevas 5-7, 7-6 (5), 7-6 (8) to reach the quarterfinals in Santiago, Chile.
Cuevas squandered two match points in the third-set tiebreaker before Olivo sealed the win on his second match point.
Sixth-seeded Bolivian Hugo Dellien will get the next chance to take down Olivo after beating Chilean wild-card entrant Marcelo Tomas Barrios Vera 6-3, 7-6 (2).
Second-seeded Casper Ruud of Norway and seventh-seeded Federico Delbonis of Argentina registered straight-set wins.
--Field Level Media