Make that No. 10 for Rafael Nadal…

The 31-year-old Spanish tennis star defeated Diego Schwartzman 6-3, 6-7 (4), 6-3, 6-3 in a hard-fought, nearly four-hour match to earn his spot in a 10th Australian Open quarterfinal.

“A great battle … he’s a good friend of mine,” Nadal said of his Argentine competitor. “This is the first big match that I played in 2018. One match like this probably helps. That’s confidence for myself, that’s confidence I can resist for four hours on court at a good intensity.”

Nadal lost last year’s Australian Open final in five sets to Roger Federer, but went on to regain the No. 1 ranking and win the French Open and US Open titles before bringing his season to a premature end because of an injured right knee.

He didn’t play a competitive match before the season-opening major, and advanced through three rounds without dropping a set.

That streak ended when Schwartzman took the second set to level the match, rebounding three times after dropping serve to break back against Nadal.

The crucial second game of the fourth set lasted almost 13 minutes and 20 points, with Nadal finally holding after saving five break points as Schwartzman attacked him with everything he had.

The 16-time major winner broke again in the next game and withstood more break points — seven in all in the last set and 15 of 18 in the match — before breaking Schwartzman’s serve in the final game and clinching it on his third match point in 3 hours, 51 minutes.

Nadal will next play sixth-seeded Marin Cilic, who collected his 100th Grand Slam match win with a 6-7 (2), 6-3, 7-6 (0), 7-6 (3) victory over No. 10 Pablo Carreno Busta.