Finland's Emil Ruusuvuori never lost his serve en route to a 6-4, 7-6 (3) win over second-seeded Hubert Hurkacz of Poland on Wednesday in the second round of the Citi Open in Washington.
Ruusuvuori went 4-for-4 on break points on his own serve, and he converted his only break point on Hurkacz's serve for a 3-2 lead in the first set.
Sixth-seeded Denis Shapovalov of Canada also stumbled in the second round, falling 6-2, 6-7 (5), 6-3 to the United States' J.J. Wolf. Japan's Yoshihito Nishioka topped 11th-seeded Alex de Minaur of Australia 3-6, 7-6 (6), 6-2, and the United States' Sebastian Korda routed 12th-seeded Sebastian Baez of Argentina 6-1, 6-4.
Nick Kyrgios, who made his first career Grand Slam final last month at Wimbledon, beat 14th-seeded Tommy Paul of the United States 6-3, 6-4.
Other second-round winners included four Americans, third-seeded Taylor Fritz, fourth-seeded Reilly Opelka, 10th-seeded Frances Tiafoe and 13th-seeded Maxime Cressy. Also advancing were fifth-seeded Grigor Dimitrov of Bulgaria, ninth-seeded Holger Rune of Denmark and Mikael Ymer of Sweden.
Abierto de Tenis Mifel
The first three seeded players in action on Wednesday at Los Cabos, Mexico, all won their second-round matches.
Second-seeded Felix Auger-Aliassime of Canada earned a 6-3, 7-5 win over Mexico wild card Alex Hernandez. Fourth-seeded Miomir Kecmanovic of Serbia cruised past Australia's Jordan Thompson 6-4, 6-2, and sixth-seeded Brandon Nakashima of the United States dumped Australia's Max Purcell 6-3, 6-3.
Top-seeded Daniil Medvedev of Russia, third-seeded Cameron Norrie of Great Britain and seventh-seeded Thanasi Kokkinakis of Australia were all due to play later Wednesday night.
--Field Level Media