Daniil Medvedev, No. 3 seed in Montreal, loses opener to Alejandro Davidovich Fokina

Former US Open champion Daniil Medvedev's prep for Flushing Meadows was cut short in Canada. The No. 3 seed at the National Bank Open fell in his opening-round match to 42nd-ranked Alejandro Davidovich Fokina, 6-4, 1-6, 6-2.

The Spaniard entered the contest 0-4 against Medvedev, and after having defeated the Russian's doubles partner in Montreal, Roman Safiullin, 6-2, 7-5. He did not play Wimbledon due to a back injury but has entered all three summer hard-court tournaments in North America, reaching the quarters in Atlanta and the round of 16 in Washington, D.C.

All four seeds in Davidovich Fokina's quarter of the draw were eliminated in the round of 32—Medvedev, No. 8 Stefanos Tsitsipas (to Kei Nishikori), No. 12 Ugo Humbert (to Nuno Borges) and No. 16 Karen Khachanov (to Matteo Arnaldi). The 25-year-old will face Arnaldi, with legitimate semifinal hopes at stake.

Medvedev, meanwhile, will continue playing in doubles—him and Safiullin advanced to the quarterfinals in a 10-point match tiebreaker—before turning his attention to the next Masters 1000 tournament in Cincinnati.

Another prominent player, No. 10 seed Tommy Paul, lost to Brandon Nakashima, 6-2, 6-7 (5), 6-1. Meanwhile, No. 1 Jannik Sinner, No. 2 Alexander Zverev, No. 5 Andrey Rublev and No. 7 Grigor Dimitrov all advanced in straight sets. Sinner, who withdrew from the Olympic Games due to tonsillitis, defeated Borna Coric, 6-2, 6-4.

In Toronto, No. 1 seed Coco Gauff defeated Yafan Wang, 6-4, 6-4. The American joined compatriots Emma Navarro, Taylor Townsend and Peyton Stearns in victory. Navarro and Townsend prevailed in straight sets, while Stearns advanced when Madison Keys retired due to injury.

Keys also retired at Wimbledon, after at one point leading eventual runner-up Jasmine Paolini by a set and 5-2.