ROME (AFP) - Women's tennis world No. 1 Naomi Osaka has pulled out of the Italian Open before Friday's (May 17) quarter-finals with injury.
The 21-year-old withdrew because of a "pain in her right hand", the organisers announced.
The Japanese star, who won the two most recent Grand Slam tournaments, was due to meet Madrid Open champion and sixth seed Kiki Bertens for a place in the final four in Rome.
Men's world No. 3 Roger Federer suffered the same fate, pulling out before his quarter-final with a right leg injury.
Federer, a four-time Rome finalist, had been due to meet Greek eighth seed Stefanos Tsitsipas for a place in the semi-finals.
The Swiss 20-time Grand Slam winner was playing in Rome to prepare for his return to the French Open for the first time since 2015.
“I am disappointed that I will not be able to compete today,” he said. “I am not 100 per cent physically and after consultation with my team, it was determined that I not play.
“Rome has always been one of my favourite cities to visit and I hope to be back next year.”
Osaka won twice on Thursday after the previous day's play was rained off, retaining the top ranking ahead of Roland Garros.
She eased into the last eight in Rome with a 6-3, 6-3 win over Mihaela Buzarnescu.
Osaka defeated the 29th-ranked Romanian in 78 minutes, after earlier beating Slovak Dominika Cibulkova by the same scoreline in one hour and 42 minutes in the second round, as players doubled up after the previous day was washed out.
At the start of the day, she had needed to make the quarter-finals to ensure Romanian Simona Halep could not swipe the No. 1 ranking and with it top seeding in the French Open starting on May 26.
But Osaka's top spot was guaranteed when reigning Roland Garros champion Halep fell to Czech Marketa Vondrousova 2-6, 7-5, 6-3 in the second round.
"Of course, it's a relief (to be top seed at Roland Garros) because that definitely was a very big goal of mine."
Osaka, who broke through by winning the US Open last year and Australian Open this year, did not survive the second round in her two previous appearances in Rome.
Before this year, she had never made the last eight of any clay tournament, but has now also reached the semi-finals in Stuttgart and quarter-finals in Madrid as she warms up for the second Grand Slam of the season in Paris.
Federer had been on court nearly four hours on Thursday as competitors played two matches after rain delays midweek.
The 37-year-old saved two match points to win through 2-6, 6-4, 7-6 (9-7) against Borna Coric to advance to the quarter-finals after earlier easing to a straight-sets win over Portugal’s Joaa Suosa.
The former world No. 1 had been a late addition to the Rome tournament as he sought clay-court practice ahead of his bid to add to his lone French Open title in 2009.
Tsitsipas will play either defending champion Rafael Nadal or Fernando Verdasco for a place in the final.