CINCINNATI (Ohio) • Rafael Nadal, poised to reclaim the world No. 1 ranking, has some advice for men's tennis stars who are in danger of missing the US Open due to injury - just accept it and keep going.

The 31-year-old Spaniard defeated France's Richard Gasquet 6-3, 6-4 on Wednesday to reach the third round at the Cincinnati Masters, the last major US Open tune-up event with the year's final Grand Slam starting on Aug 28 in New York.

Nadal, a 15-time Grand Slam winner nagged by knee injuries for years, will overtake Andy Murray atop the rankings on Monday with the Scot sidelined by a hip injury.

He was assured of the top spot for the first time since July 2014 when 19-time Grand Slam winner Roger Federer withdrew from Cincinnati with a back injury.

"I worked a lot to give (myself) another chance and here I am," Nadal said.

"Just to be back to that position makes me happy and of course it's going to be an emotional moment for me."

Serbian 12-time Grand Slam champion Novak Djokovic will miss the remainder of the year with an elbow injury, as will 2016 US Open champion Stan Wawrinka with a knee injury and Kei Nishikori with a torn right wrist tendon.

Add Marin Cilic with an adductor injury and Milos Raonic withdrawing with a left wrist injury, and seven of the world's top 10 are absent this week.

Nadal knows all too well how that feels. He has missed six Grand Slam events in the 13 years since he began winning such titles.

"I have been in that position more than all these players that are out now," he added.

"I know how tough it is. I'm very sorry for all of them and I wish all of them a fast and good recovery.

"But at the same time I tell you I'm the only one of these top players that missed a lot of important tournaments in my career. More than (anybody) else, I know how tough it is.

"The only thing that you can do when these kind of things happen is accept and keep going."

While Nadal easily extended his winning run over Gasquet to 15-0, it was otherwise a day of upsets at Cincinnati.

Unseeded American teenager Frances Tiafoe beat world No. 7 Alexander Zverev 4-6, 6-3, 6-4 in the second round.

Zverev, who stunned Federer in the Montreal ATP tournament final last week after claiming the title in Washington DC, was on a 10-match winning streak but faded in the final set against energetic baseliner Tiafoe.

In the women's competition, Germany's third-ranked Angelique Kerber, who surrendered the top ranking after Wimbledon, lost her chance to reclaim it by falling to Russia's Ekaterina Makarova 6-4, 1-6, 7-6 (13-11).

"I think it was an up-and-down match," Kerber said.

"I was finding my rhythm actually in the second set. But I had the chance as well in the first set. She played well then. In the end it was just one point which decided the match."

Ninth-ranked Venus Williams of the United States also crashed out of the second round when she lost to Australian 48th-ranked qualifier Ashleigh Barty 6-3, 2-6, 6-2.

"I'm going to take a break and have a rest," Williams said.

"I'm just planning on being super rested (before the US Open)."

AGENCE FRANCE-PRESSE, REUTERS

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