TORONTO — 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).
