Alexander Zverev overcomes defending champ Alexei Popyrin in Toronto quarterfinals

TORONTO (AP) — Top-seeded Alexander Zverev rallied to defeat No. 18 Alexei Popyrin of Australia 6-7 (8), 6-4, 6-3 on Monday to reach the semifinals of the National Bank Open.

Zverev, the 2017 tournament champion, will face No. 11 seed Karen Khachanov of Russia, who beat No. 26 Alex Michelsen of the U.S. 6-4, 7-6 (3).

Zverev, a German who is ranked No. 3, advanced to his 75th ATP Tour semifinal. He is looking for his 25th tournament title and eighth in an ATP 1000 Masters tournament.

The other quarterfinals are Tuesday. Second-seeded Taylor Fritz will take on No. 6 Andrey Rublev of Russia, while No. 4 Ben Shelton is slated to meet No. 9 Alex de Minaur of Australia. Both semifinals go Wednesday ahead of Thursday's title match.

Popyrin took the first set when his gentle backhand volley after a long rally grazed the top of the net and dropped for the winning point — much to the delight of his fans, including one with an inflatable yellow kangaroo.

Zverev responded by immediately firing a ball completely out of Sobeys Stadium in frustration, but quickly regrouped to go up 2-0 in the second set.

Popyrin grabbed a break of his own before holding serve at 4-4. Zverev, who won the Canadian title in Montreal eight years ago when he defeated childhood idol Roger Federer, took a 5-4 lead and then again broke his opponent to even the match.

Ousted at the quarterfinal stage of last year's tournament, Zverev got another break to go up 2-0 in the third set before serving out the match.

The 28-year-old, who lost to top-ranked Jannik Sinner in the final at this year's Australian Open and made the French Open quarters, improved to 4-0 all-time against Popyrin, including a third-round victory at the Paris Olympics.

Zverev has two tournament wins on clay this year, and is the highest-ranked player competing in a Toronto field lacking some significant star power after Sinner, No. 2 Carlos Alcaraz, No. 5 Jack Draper and No. 6 Novak Djokovic all skipped the hard-court event.

The 25-year-old Popyrin, ranked No. 26, had his nine-match winning streak in Canada snapped.