Rafael Nadal runs down a backhand return against Nikoloz Basilashvili during...

Rafael Nadal runs down a backhand return against Nikoloz Basilashvili during their fourth round men's singles match at Arthur Ashe Stadium on Sunday. Credit: Joseph D. Sullivan

Rafael Nadal does not have a handlebar mustache. And even if he did, it is highly unlikely that he would twirl it. There is menace in Nadal’s tennis, a dastardly persistence, but no evil is his demeanor.

On Sunday, he chased Nikoloz Basilashvili, the first player from the Republic of Georgia ever to reach the U.S. Open’s fourth round, out of the tournament in a 6-3, 6-3, 6-7 (6), 6-4 victory. Then he complimented the 37th-ranked Basilashvili for playing a better tiebreaker than himself and assured that his own status — the world’s No. 1 ranking and 17 major-tournament championships, second only to Roger Federer’s record 20 — had nothing to do with the business at hand.

“No, no. Just play well,” Nadal said. “At the end of the day, it’s not about experience, not about pressure or any of that stuff. I have been in that position a lot of times in my career. It’s always about playing well. If I play well, other things I can manage.”

By the time Basilashvili offered any real resistance in the match, Nadal already had a two-sets-to-love lead and his play hinted at a straight-sets decision. Then, he said, “the match became more difficult.” Nadal missed a couple of forehands in the tiebreaker, one sent wide to give Basilashvili a set point, which Basilashvili converted with a lovely backhand drop volley.

But for most of the three hours and 19 minutes, Basilashvili served as a backdrop for Nadal’s familiar work routine — a tireless game, mostly from the baseline, of muscle and movement.

“I’ve never worked too hard with weights,” Nadal said when asked about the source of his power. “My body is how it is. I work every day to feel myself strong enough to hold the pains that I normally have.

“For me, the most important, of course, the knees. So important.”

There has been some speculation that his right knee is bothering him now, though Nadal refused — as he always does — to discuss any physical limitations during a tournament. “But if I must choose one important part of the body, is abdominal and back,” he said. “That gives you the possibility of stabilizing the rest of the body. Have that part of the body strong and fit, you know, makes the right balance on everything.”

It is Nadal’s habit to insist that he never looks past his next match. That will be a quarterfinal against No. 9 seed Dominic Thiem on Tuesday. But should he win three more matches and claim his fourth U.S. Open title, perhaps his physical strength might come in handy to lift the 19.5-inch tall championship trophy?

“It’s not very, very heavy,” Nadal said. (In fact, just seven pounds.)

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