NEW YORK (AFP) — Rafael Nadal overcame a freak injury scare when he accidentally hit himself with his own racquet to reach the US Open third round on Thursday as Serena Williams saw one chapter of her epic tennis journey close.

Nadal defeated Italy's Fabio Fognini 2-6, 6-4, 6-2, 6-1 but only after suffering a bizarre self-inflicted injury when leading 3-0 in the fourth set.

The four-time champion, and holder of a men's record 22 Grand Slam titles, was hurt when his racket bounced back off the court as he stretched for a ball and hit him squarely on the nose.

The 36-year-old Australian and French Open champion dropped his racket to the Arthur Ashe Stadium floor and sprinted to the sidelines where he lay on his back with his nose bloodied.

He required a medical timeout to have the wound tended before resuming with a bandage across the bridge of his nose.

"I was a little bit dizzy and it was a little bit painful," said Nadal, who said he had suffered a similar injury in the past caused by a golf club.

Nadal said that despite being a set and 4-2 down, he was happy to have recovered after coming into the tournament still worried by the abdominal injury he suffered at Wimbledon.

"I had to play better. It was one of the worst starts ever for me," he said.

"It has been tough in the last month so I knew these kind of things can happen."

For the first time since 2018, Serena and Venus Williams revived a partnership which has brought them 14 doubles titles at the majors.

However, their hopes of collecting a third crown in New York were dashed in a 7-6 (7/5), 6-4 defeat to Czech pairing Linda Noskova and Lucie Hradecka.

The loss leaves 40-year-old Serena free to focus on what is widely expected to be the final singles campaign of her landmark 27-year career before retirement.

On Friday, the 23-time Slam singles winner will face Australia's Ajla Tomljanovic for a place in the fourth round.

Serena and her 42-year-old sister went down fighting, clawing back from 1-4 down in the second set before the Czech pair steadied the ship.

"I'm still in shock," Hradecka said.

Meanwhile, Victoria Azarenka triumphed against Marta Kostyuk 6-2, 6-3 in a match dominated by bitter exchanges over the conflict in Ukraine.

Last week, Belarusian star Azarenka was axed from an exhibition event aimed at raising money for the war-ravaged country.

Ukraine's Kostyuk had refused to take part in protest at the presence of Azarenka who she has criticised for a perceived failure to condemn the invasion of her home country.

Belarus is a close ally of Russia and has allowed Moscow to use its territory to launch attacks into Ukraine.

The tension between the two was evident at the end of their tie on Court 17 with Kostyuk offering just a touch of racquets instead of the customary post-match handshake.

"How did it make me feel? It's not the most important thing in the world right now," Azarenka said.