Greek teen Tsitsipas upsets defending champ Zverev

Stefanos Tsitsipas of Greece hits a forehand to Alexander Zverev of Germany during Rogers Cup quarterfinal tennis tournament action in Toronto on Frid

Stefanos Tsitsipas of Greece hits a forehand to Alexander Zverev of Germany during Rogers Cup quarterfinal tennis tournament action in Toronto on Frid

Stefanos Tsitsipas of Greece hits a forehand to Alexander Zverev of Germany during Rogers Cup quarterfinal tennis tournament action in Toronto on Frid

Stefanos Tsitsipas of Greece hits a forehand to Alexander Zverev of Germany during Rogers Cup quarterfinal tennis tournament action in Toronto on Frid

Alexander Zverev, of Germany, reacts during his loss to Stefanos Tsitsipas, of Greece, in Rogers Cup quarterfinal tennis tournament action in Toronto,

Alexander Zverev, of Germany, reacts during his loss to Stefanos Tsitsipas, of Greece, in Rogers Cup quarterfinal tennis tournament action in Toronto,

Alexander Zverev of Germany hits a backhand to Stefanos Tsitsipas of Greece in Rogers Cup quarterfinal tennis tournament action in Toronto onFriday, A

Alexander Zverev of Germany hits a backhand to Stefanos Tsitsipas of Greece in Rogers Cup quarterfinal tennis tournament action in Toronto onFriday, A

Stefanos Tsitsipas, of Greece, reacts after defeating Alexander Zverev, of Germany, in Rogers Cup quarterfinal tennis tournament action in Toronto, Fr

Stefanos Tsitsipas, of Greece, reacts after defeating Alexander Zverev, of Germany, in Rogers Cup quarterfinal tennis tournament action in Toronto, Fr

Kevin Anderson of South Africa serves in front of sparsely filled stands on his way to defeating Grigor Dimitrov of Bulgaria during Rogers Cup quarter

Kevin Anderson of South Africa serves in front of sparsely filled stands on his way to defeating Grigor Dimitrov of Bulgaria during Rogers Cup quarter

Kevin Anderson of South Africa gets knocked off balance by a serve on his way to defeating Grigor Dimitrov of Bulgaria during Rogers Cup quarterfinal

Kevin Anderson of South Africa gets knocked off balance by a serve on his way to defeating Grigor Dimitrov of Bulgaria during Rogers Cup quarterfinal

Grigor Dimitrov of Bulgaria hits a backhand on his way to being defeated by Kevin Anderson of South Africa during Rogers Cup quarterfinal tennis tourn

Grigor Dimitrov of Bulgaria hits a backhand on his way to being defeated by Kevin Anderson of South Africa during Rogers Cup quarterfinal tennis tourn

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.