Toronto R4 previews and predictions: Zverev vs. Cerundolo, Rune vs. Popyrin

Quarterfinal spots at the Toronto Masters will be handed out on Saturday, when top seed Alexander Zverev faces Francisco Cerundolo. Holger Rune and defending champ Alexei Popyrin are also taking the court.

(1) Alexander Zverev vs. (14) Francisco Cerundolo

Zverev and Cerundolo will be going head-to-head for the fourth time in their careers when they clash in round four of the National Bank Open on Saturday. Surprisingly, all three of their previous encounters have gone Cerundolo’s way. The 24th-ranked Argentine prevailed 6-3, 6-4 at the 2024 Madrid Masters, 3-6, 6-3, 6-2 in Buenos Aires earlier this season, and 7-5, 6-3 in a recent Madrid rematch.

Although Zverev at one stage of the 2025 campaign saw the door to the No. 1 ranking open wide, but now he is struggling to simply to maintain the No. 3 position ahead of Taylor Fritz. The 28-year-old German has defeated Adam Walton and Matteo Arnaldi so far in Toronto, but neither performance was convincing. Cerundolo had also been scuffling, but he he advanced to the last 16 by beating Jaume Munar and Tomas Martin Etcheverry. Both of these guys are all-court players, so a move from clay to hard courts should not impact the matchup to a significant extent. Unless Zverev can suddenly equal Cerundolo in forehand bravery (and that isn’t likely), the No. 14 seed could be in line for another upset.

Pick: Cerundolo in 3

(18) Alexei Popyrin vs. (5) Holger Rune

Popyrin is officially the defending champion of this Masters 1000 tournament, even though last year it was played in Montreal instead of Toronto. A change in location does not seem to have altered Popyrin’s comfort level. The 26th-ranked Australian is once again making noise, having followed up a victory over Nicolas Arseneault by beating Daniil Medvedev 5-7, 6-4, 6-4 on Thursday night.

Up next for Popyrin on Saturday is a second meeting with Rune, who won their only previous contest 6-4, 5-7, 6-4 at the 2023 Rome Masters. The ninth-ranked Dane is somewhat of a question mark at the moment, as he lost right away at Wimbledon to Nicolas Jarry (from two sets up) and then withdrew from Washington, D.C. because of a back injury. Toronto wins over Giovanni Mpetshi Perricard and Alexandre Muller are encouraging signs, but they hardly provide proof of Rune being back to his best. This is a good opportunity for Popyrin to pick up yet another victory north of the border.

Pick: Popyrin in 3