Japan's Yoshihito Nishioka fell short in his bid for a second career title Sunday in the Citi Open final, losing 6-4, 6-3 to Wimbledon runner-up Nick Kyrgios.
World No. 96 Nishioka reached the final of the U.S. Open warm-up event with a straight-sets victory over top-seeded Russian Andrey Rublev in the semis, but he was unable to win a break point against the big-serving Kyrgios.
The 63rd-ranked Australian saved all nine of Nishioka's break points while hitting 12 aces and winning 22 of 25 first-serve points at Washington's William H.G. FitzGerald Tennis Center.
With his opponent taking the initiative early, the 26-year-old Nishioka struggled to keep pace in the hot conditions.
"It's disappointing that I couldn't get my second title," Nishioka said. "I was fatigued and my opponent outplayed me. He was serving really well."
"I would've liked to have pushed him a little more. I couldn't apply enough pressure and that's why I lost."
Nishioka, who won his sole ATP title at the 2018 Shenzhen Open, was nevertheless happy to reach the final in Washington and is set to jump in the rankings.
"Getting to the final of this tournament has given me confidence," he said. "It's been a fun week."