Frances Tiafoe of Riverdale in Prince George's County defeated Alexander Zverev, 4-6, 6-3, 6-4, in the Round of 32 at the Cincinnati Masters on Wednesday to end the 20-year-old German's 10-match win streak. Zverev, ranked No. 7 in the world, had won two straight ATP World Tour events entering Wednesday's match — beating Kevin Anderson for the Citi Open title and 19-time Grand Slam champion Roger Federer for the Montreal Masters crown — and was a favorite to capture his seventh title of the year in the last major US Open hardcourt tuneup. Zverev could have matched Andre Agassi in 1995 with the only ATP Washington, Canada and Cincinnati title hat trick in a year. "I can't believe it," Tiafoe said. "To win a match like that was great for me." Tiafoe, a product of the Junior Tennis Champions Center in College Park, was previously 1-12 against players ranked among the top 50. Zverev's grueling streak finally caught up to him against Tiafoe, who was more aggressive as the match went along. "I'm completely dead right now," Zverev said. "I have been dead for the past two days. I could have easily pulled the plug in the second set, but I'm not going to retire just because I'm tired. And he's too good of a player to beat when I'm in this stage." Tiafoe, ranked No. 87, will face fellow American and No. 14 seed John Isner in the Round of 16 today at 10 a.m.