Four-time Grand Slam champion Osaka, a winner at Flushing Meadows in 2018 and 2020, was beaten 7-6 (7/5), 6-3 by 19th-seeded American Collins in a battle of two big hitters.
Collins, finalist at this year’s Australian Open, now advances to a second-round clash with Spain’s Cristina Bucsa.
Danielle Collins is into Round 2 of the #USOpen https://t.co/rUZa0hWKHx
— US Open Tennis (@usopen) 1661920283000
The 28-year-old right-hander from Florida will head into that assignment brimming with confidence after showing great composure to put away Osaka on Arthur Ashe Stadium.
Former world number one Osaka, whose ranking has fallen to 44 after an inconsistent year, made a smooth start with an early break to take a 3-0 lead.
But Collins battled back into the match and took the first set after winning a hard-fought tie-break.
With both players producing some booming groundstrokes, the second set was a question of who would blink first.
Naomi always has time for the fans 💙See you next year, champ. https://t.co/R97NqEfKFh
— US Open Tennis (@usopen) 1661920341000
Collins put herself on the threshold of victory after breaking Osaka for a 5-3 lead in the eighth game.
Osaka, 24, came within touching distance of securing the break of serve needed to keep the match alive after taking a 15-40 lead in the ninth game.
But Collins rallied back to deuce and then seized victory on her first match point when Osaka hit a return long.