TORONTO -- Stefanos Tsitsipas pulled off another upset Friday at the Rogers Cup, and top-seeded Rafael Nadal rallied at night to join the Greek teenager in the semifinals.

Tsitsipas saved two match points in a 3-6, 7-6 (11), 6-4 victory over second-seeded defending champion Alexander Zverev, and the top-seeded Nadal beat sixth-seed Marin Cilic 2-6, 6-4, 6-4.

Zverev, the 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.

Tsitsipas, 19, 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 Nadal -- who also was 19 -- in 2006 at Monte Carlo.

Tsitsipas will face fourth-seeded Kevin Anderson in the semifinals, trying to become the youngest to beat four consecutive top-10 players in an event since the ATP World Tour was established in 1990. Anderson beat fifth-seeded Grigor Dimitrov 6-2, 6-2.

Nadal will play Karen Khachanov, a 6-3, 6-1 winner over Robin Haase.