Toronto, Aug 14 (IANS): Top seed Daniil Medvedev was two points from defeat against Poland's Hubert Hurkacz, but he held his nerve to produce a fine 2-6, 7-6(6), 7-6(5) comeback to reach the National Bank Open semifinals here on Friday evening.

The Russian will take on John Isner of the US, who extended his win streak to nine matches after he halted Frenchman Gael Monfils 7-6(5), 6-4 to reach the last-four.

Medvedev is seeking his fourth ATP Masters 1000 title, and a 12th tour-level title overall.

Medvedev, whose Wimbledon campaign was cut short in the fourth round by the seventh-seeded Hurkacz just over a month ago, was out for revenge as they faced off for the second time on the ATP tour. The Russian fired 38 winners, including 23 aces, to find a way to victory against Hurkacz, who did not drop serve once in the contest.

"He had his chances and he was probably the better player for at least two sets for sure, but that's tennis," Medvedev told atptour.com. "We both have great serves and I managed to hit some aces when I needed to.

"It was definitely not easy. He was on top of me. But to win matches like this gives you a huge boost of confidence. It's a pleasure to be standing here and giving interviews."

Third seed Stefanos Tsitsipas' season continued to go from strength to strength as the Greek recorded a 45th tour-leading victory of the year to defeat Casper Ruud of Norway 6-1, 6-4 to reach the semifinals.

The 23-year-old, who rose to a career-high No. 3 in the ATP rankings earlier this week, served well throughout and hit the ball with great power and depth to advance to his seventh ATP Masters 1000 semifinal in 74 minutes.

Tsitsipas will next face Reilly Opelka after the American defeated Spaniard Roberto Bautista Agut as the Greek tries to advance to the championship match in Canada again.