Djokovic out of US Open in shock defeat by Popyrin

Frances Tiafoe avenged his defeat by Ben Shelton at last year's US Open by beating the 13th seed in an all-American five-set thriller to reach the fourth round.

The pair, who are good friends, faced each other in the quarter-finals in New York last year with Shelton emerging as the victor.

But it was the lower-ranked Tiafoe who won on Friday, coming from behind twice to triumph 4-6 7-5 6-7 (5-7) 6-4 6-3 after more than four entertaining hours on Arthur Ashe Stadium.

"Ben is an incredible player, he really is. He goes for all kinds of shots, he's got no care in the world. It's really annoying," 20th seed Tiafoe said.

Tiafoe's reward is a potential meeting with defending champion Novak Djokovic, who will continue his bid for a record 25th Grand Slam singles title when he faces Australia's Alexei Popyrin in the night session on Arthur Ashe Stadium.

Earlier, Russian Andrey Rublev was the first men's singles player to make it into the fourth round with an assured victory over Czech Jiri Lehecka.

The sixth seed had to fight back from two sets down against Arthur Rinderknech in the last round but he made lighter work of Lehecka, winning 6-3 7-5 6-4 in just over two hours.

Rublev, a 10-time Grand Slam quarter-finalist who has yet to win a major, will face Grigor Dimitrov after the Bulgarian ninth seed claimed a dominant 6-3 6-3 6-1 win over Dutchman Tallon Griekspoor.

Meanwhile, American 12th seed Taylor Fritz continued his perfect run in New York with a 6-3 6-4 6-2 victory against Argentina's Francisco Comesana.

Fritz, who has yet to drop a set, will face Norway's Casper Ruud, a finalist in 2022, or Shang Juncheng of China in the fourth round.