World number one Naomi Osaka will continue her US Open title defence on Monday when she faces Belinda Bencic for a place in the quarter-finals.

The 21-year-old won her first Grand Slam at Flushing Meadows last year but has lost two of her three previous meetings with the Swiss 13th seed.

"The thing with me is I get better as the tournament goes on," said Osaka.

Three-time champion Rafael Nadal takes on 2014 winner Marin Cilic in the Arthur Ashe Stadium night session.

Japan's Osaka was involved in an emotional embrace with Coco Gauff in the previous round after she beat the 15-year-old 6-3 6-0.

Osaka, who won her second Grand Slam title at the Australian Open in January, says she "trusts myself more" in the latter stages of tournaments.

"The last two times I was in the round of 16, I won it, if that answers... I don't want to say that. That's bold.

"I'm just out here trying my best. I'm just going with the flow at this rate. I've never defended a Grand Slam before."

Her match against 22-year-old Bencic, who is looking to reach the quarter-finals in New York for a second time, will be first on Ashe from 17:00 BST.

In the other women's singles last-16 matches, 19-year-old Canadian Bianca Andreescu plays American Taylor Townsend, Kristie Ahn, also from the US, faces Belgian 25th seed Elise Mertens and Croatia's Donna Vekic takes on Germany's Julia Gorges.

Nadal's moment to 'make a step forward'

Spaniard Nadal is the men's second seed and has a favourable draw with long-term rivals Novak Djokovic and Roger Federer placed in the other half.

Nadal has enjoyed a relatively easy passage to the last 16, winning two matches in straight sets and having a walkover in the second round when Thanasi Kokkinakis withdrew through injury.

But the 33-year-old said "you never know what's better or worse" when it comes to time spent on court.

"Now is the moment to push, to make a step forward if I want to give me a chance to fight for the important things," he said. "That's what I'm going to try."

Cilic said he must "serve well" and be a "little bit aggressive" to impose himself on Nadal.

"I'm going to have to be ready for a tough battle. Hopefully I'm going to win that one," added the Croat.

Either German sixth seed Alexander Zverev, 22, or 27-year-old Argentine Diego Schwartzman, who follow Osaka and Bencic on Ashe, will face the winner.

Meanwhile, unseeded Russian Andrey Rublev plays Italian 24th seed Matteo Berrettini and French 13th seed Gael Monfils takes on Spaniard Pablo Andujar.