TORONTO (AP) -- Greek teenager Stefanos Tsitsipas pulled off another upset Friday at the Rogers Cup, beating defending champion Alexander Zverev 3-6, 7-6 (11), 6-4 in the quarterfinals.
Zverev, the second-seeded German star coming off a victory last week in Washington, double-faulted on match point to send Tsitsipas to his first ATP World Tour Masters 1000 semifinal.
The 19-year-old Tsitsipas beat seventh-seeded Dominic Thiem and ninth-seeded Novak Djokovic to reach the quarterfinals. He's the youngest player to beat three top-10 players in one tournament since Rafael Nadal -- who also was 19 -- in 2006 at Monte Carlo.
Tsitsipas will face fourth-seeded Kevin Anderson in the semifinals at Aviva Centre. Anderson beat fifth-seeded Grigor Dimitrov 6-2, 6-2.
In the night quarterfinals, the top-seeded Nadal faced sixth-seeded Marin Cilic, while Robin Haase played Karen Khachanov.