Tenth-seeded Taylor Fritz was one of four Americans to win on Tuesday, defeating Andy Murray of Great Britain 6-1, 6-3 in the first round of the National Bank Open in Montreal.
Fritz posted five aces to Murray's one as he improved to 31-12 on the season.
"It's an honor to be on the court with Andy," Fritz said. "Just to get the chance to play him, he's been around, he's been dominating since before I came on Tour and basically the whole time I've been on Tour.
"I haven't always played well this part of the year before the U.S. Open, so it feels really good this year, it just seems different. I'm playing good tennis right now."
Maxime Cressy, Tommy Paul and Tiafoe were the other three Americans to come out on top. Cressy defeated Russian Aslan Karatsev 6-4, 6-4, Paul knocked off Canadian wild card Vasek Pospisil 6-4, 6-4 and Tiafoe outlasted France's Banjamin Bonzi 6-7 (6), 7-5, 6-3..
Fritz is set to play Tiafoe in his next match.
Ninth-seeded Cameron Norrie, qualifier Jack Draper and Daniel Evans made up for Murray's loss, though, as all three Brits won their respective matches.
Norrie bested American Brandon Nakashima 6-4, 6-4, while Draper also won in straight sets, toppling French qualifier Hugo Gaston 6-2, 6-3. Evans took home a 6-2, 1-6, 6-0 victory against Filip Krajinovic of Serbia.
A pair of Spaniards also found success, as Pablo Carreno Busta upset No. 11 Matteo Berrettini of Italy 6-3, 6-2, and No. 14 seed Roberto Bautista Agut slid past American qualifier Marcos Giron 7-6 (5), 6-3.
It was nearly a perfect day for Spain, but Pedro Martinez was dealt a 7-6 (4), 3-6, 6-2 loss by 17th-seeded Frenchman Gael Monfils.
Berrettini was the only seeded player to fall on Tuesday.
Also, 13th-seeded Marin Cilic of Croatia claimed a 6-3, 6-2 win over fellow countryman Borna Coric, who was playing on a protected ranking. No. 15 Grigor Dimitrov of Bulgaria defeated Canadian wild card Alexis Galarneau 6-4, 7-5.
In other action, Australian Alex de Minaur beat Canadian Denis Shapovalov 7-5, 7-6 (4), and Nick Kyrgios, also of Australia, cruised past Argentina's Sebastian Baez 6-4, 6-4. In a battle of French qualifiers, Adrian Mannarino defeated Arthur Rinderknech 6-3, 6-3.
Japan's Yoshihito Nishioka and Denmark's Holger Rune also won their matches.
--Field Level Media