Coco Gauff's quest for a second US Open crown was halted in stunning fashion as Naomi Osaka triumphed in straight sets on Monday.

Osaka is a two-time champion at Flushing Meadows, but went into her round-of-16 tie with world number three Gauff as the underdog.

Yet the four-time major winner needed just 64 minutes to complete a superb 6-3 6-2 victory.

She sealed the win at the first time of asking, breaking Gauff for the fourth time when the American failed to beat the net.

Osaka, who reached the final of the Canadian Open last month, has booked her place in the last eight at Flushing Meadows for the first time since winning the second of her two titles in New York in 2020.

"I'm a little sensitive and I don't wanna cry, but I had so much fun out here," said a jubilant Osaka.

"I was in the stands two months after I gave birth to my daughter watching Coco, I really wanted an opportunity to come back here and play.

"This is my favourite court in the world and it means so much to me to be back here. I just wanna say a big thank you to my team, it hasn't always been easy but they've been by my side so thank you and love you.

"It's definitely really special [to beat Gauff], I look up to her a lot I think the way she conducts herself is really special and I feel like to be such an amazing role model at such a young age is a gift and a talent she has. I have all the respect in the world for her."

27 - Naomi Osaka has registered her 27th win in Women’s Singles at the US Open, it is her most at a single WTA-level event during her career, eclipsing Australian Open where she has 26. Den. #USOpen | @usopen @WTA @WTA_insider pic.twitter.com/E5oSWRFDOq

— OptaAce (@OptaAce) September 1, 2025

Data Debrief: Osaka to go all the way?

This is the first time Osaka has reached the quarter-finals of a major since doing so at the Australian Open in 2021 - a tournament she won. In fact, every time she has progressed beyond the last 16 at a grand slam, the 27-year-old has gone on to claim the title.

Osaka has now registered her 27th match win at the US Open. At no other WTA-level event has she won as many matches.

She is just the second player in the Open Era, after Flavia Pennetta, to reach her first five grand slam quarter-finals on hard courts.