Monfils, one of three French men still in action in the fourth round, awaits either two-time champion Rafael Nadal of Spain or 22-year-old compatriot Lucas Pouille.

Monfils, in the quarters for the third time, produced nine aces and broke Baghdatis six times as the Cypriot managed to put just 36 percent of his first serves in play.

The 10th-seeded Monfils is brimming with confidence after an impressive hardcourt build up to the Open that included the biggest ATP title of his career at the 500 level tournament in Washington.

On a busy day for French players, ninth-seeded Jo-Wilfried Tsonga of was out to spoil the hopes of home fans when he took on the lone American left in the men's draw, Jack Sock.

Fourth-seeded Nadal's clash with Pouille highlighted the afternoon session on Arthur Ashe stadium.

The Spaniard, forced out of the third round of the French Open with a wrist injury that also sidelined him from Wimbledon, is seeking his first US Open quarter-final since he won the title for a second time three years ago.

"For me it's great news that I am on the tour again and I am playing every day with less pain in the wrist," Nadal said after dispatching Andrey Kuznetsov in straight sets in the third round.

Nadal won his only prior meeting with Pouille, in Monte Carlo last year. 

But he said he expected a tough test from a player who reached his first ATP final at Bucharest this year, made it to the quarters at Wimbledon and achieved a career-high ranking of 21 in the world in July.

"He has all the shots: good serve, good forehand, good backhand," Nadal said. "He's a tough opponent."

World number one Novak Djokovic was also in action against one of the ATP tour's rising youngsters in 21-year-old Briton Kyle Edmund.

Edmund is in the last 16 of a Grand Slam for the first time in his first appearance in the US Open main draw.

Djokovic, meanwhile, is 9-0 in US Open fourth-round appearances.

Although he struggled through a first-round victory over Jerzy Janowicz, Djokovic hasn't broken a sweat since. 

He was given a walkover in the second round by injured Czech Jiri Vesely and played just six games before third round opponent Mikhail Youzhny retired hurt.

The extra rest may prove providential for Djokovic, who has battled a left wrist injury and received treatment on his right arm during his win over Janowicz.

Edmund, who has already ousted 13th-seeded Richard Gasquet and the big-serving 20th seed John Isner, said he'd be ready to go the distance against Djokovic.

"I'm ready to go," said Edmund, who in the absence of Andy Murray led Britain into the semi-finals of the Davis Cup in July. "I'll be on the court."
The arrival of Murray and Edmund in the round of 16 marks the first time two British men have reached the fourth round of the US championships since 1966.

Murray will take on Bulgarian Grigor Dimitrov on Monday, when third-seeded Stan Wawrinka, sixth-seeded Kei Nishikori of Japan, eighth-seeded Austrian Dominic Thiem and former champion Juan Martin del Potro will also battle for quarter-final berths.