Zverev held his nerve in the deciding set to win 6-4, 3-6, 6-2, 4-6, 6-3 and advance to his 10th major quarter-final on Tuesday. the 12th seeded Sinner battled with his physical struggle in the second and third sets but roared back into contention with a courageous fourth-set performance.
Zverev overcame the former World No. 3 with 6-7(2), 7-6(8), 6-1, and 6-1. The German, who has advanced to the Round of 16 in each of his last four tournament appearances, will face sixth-seeded Jannik Sinner, who earlier in the day defeated 2016 US Open winner Stan Wawrinka in four sets.
Reigning US Open winner and World No.1 Carlos Alcaraz will start his title defence against Dominik Koepfer and could meet sixth seed Jannik Sinner in the quarterfinals.
The Italian produced a clean-hitting performance in Toronto to register a 6-4, 6-1 victory against Alex de Minaur in a match that lasted for one hour and 30 minutes.
Sinner's success in this match continues his solid run in ATP Masters 1000 events this year, which includes semifinal finishes at Indian Wells and Monte Carlo and a Miami final appearance. The Italian is 17-4 this season and is enjoying a solid run.
The 23-time grand slam champion leads Wawrinka 21-6, head-to-head. This was their just third meeting since the final of the 2016 US Open, which the Swiss player won.
Alcaraz continued his perfect record at this year's Wimbledon on Friday when he moved past Frenchman with a controlled display against World No. 84 Muller.