Rafael Nadal could not find his form Thursday night in a second-round struggle at the U.S. Open, a squeaker of a win over Fabio Fognini during which the Spaniard bloodied himself when his own racket ricocheted off the court and hit the bridge of his nose.

One round and two days later, Nadal found the perfect remedy: his personal punching bag.

The second-seeded Nadal cruised past Richard Gasquet for the 18th time as a professional, remaining undefeated against his childhood friend, in a 6-0, 6-1, 7-5 win Saturday night at Arthur Ashe Stadium.

“That was my best match in the tournament,” Nadal said after his first straight-sets victory in this Open. “Important improvement. Have to keep going.”

Nadal, the 22-time Grand Slam champion is four wins away from his third Grand Slam win this year. He will face 22nd-seeded American Frances Tiafoe — whom Nadal called a “great player” — in the Round of 16.

Until the fourth game of the second set, Nadal did not lose a game to Gasquet. By that point, a pro-Nadal crowd had temporarily switched its allegiance and had begun pulling for the underdog, trying to power Gasquet, perhaps not to a win, but at least to a competitive match.

The crowd got on its feet to applaud the 36-year-old Gasquet as he took the game — more than an hour into the match — but one game could not bring him far. The Frenchman has not won a set from Nadal since 2008, losing 34 straight, though he came close in the third set Saturday.

Gasquet made his first and only charge when he won four straight games in the third set by rushing the net more often, and went ahead 5-4.

But Nadal, both 36 and ageless, responded by winning the last three games of the match. Nadal finished off Gasquet with a powerful serve that led to a backhand forced error, and then allowed his emotion to be expressed by a pumped fist.

“I went through some difficult moments,” said Nadal, who won the Australian Open in January and the French Open in June. “That’s something that is good that I went through that.”

Nadal won 100 points to 71 from Gasquet, who seemed to have chances all match, but never could win them when they mattered.

Gasquet won just one of seven break points in a match that, until the third set, was filled with long rallies from behind the baseline, playing right into Nadal’s hands.

Better than playing into his nose.