World number 10 Taylor Fritz captured his 250th hardcourt victory on Monday by defeating Belgium's Zizou Bergs in the first round of the ATP and WTA Washington Open.
The American third seed, seeking his 11th ATP tour title and first Eastbourne last year, needed only 79 minutes to complete a 6-3, 6-4 triumph.
Wimbledon quarterfinalist Fritz will next face either countryman Tommy Paul or Poland's Kamil Majchrzak.
"He had a few break chances, but when I served out the first and went up a break in the second, I felt like the momentum was on my side," Fritz said.
"It's really good to get out of those games and to finish the match unbroken."
Britain's Jack Draper withdrew from the event with a left arm injury after also missing Wimbledon.
"These last months have felt like nothing but adversity and setbacks," the former world No 4 Draper wrote on Instagram.
"Most days I've spent in doubt, yet hopeful that I can keep taking positive steps forward and finding ways to progress."
American lucky loser Mackenzie McDonald replaced Draper.
Japan's Kei Nishikori, the 2015 Washington champion who will retire at the end of season, beat China's Shang Juncheng 6-7 (3/7), 6-3, 6-4 in two hours and 31 minutes in his first ATP tour match this year.
"It was not easy," the 36-year-old Nishikori said after his first ATP tour victory in 14 months.
"I started playing better in the second set and, especially in the third set, I think I played really solid."
France's 56th-ranked Terence Atmane upset sixth-seeded hometown hero Frances Tiafoe 4-6, 6-3, 6-4 in two hours and five minutes.
Australian top seed and defending champion Alex de Minaur will face Greece's Stefanos Tsitsipas on Tuesday.
In the women's draw, defending champion and seventh seed Leylah Fernandez beat Poland's Magda Linette 6-1, 6-4.
"Overall my game was solid. I didn't give away too many free points, which definitely helped a lot," said the Canadian 2021 US Open runner-up Fernandez.
"I'm feeling very good. So many good memories so starting off a win definitely helps."
Fernandez will next meet either Alexandra Eala of the Philippines or China's Zheng Qinwen.
Russian Liudmila Samsonova, the 2022 Washington winner, outlasted American sixth seed Madison Keys 3-6, 6-4, 6-4.
Venus Williams, 46, rolled back the years to win her doubles opener with Russia's Diana Shnaider 6-3, 6-4 over Ulrikke Eikeri of Norway and American Quinn Gleason.