MELBOURNE  — Rafael Nadal never truly seemed in danger of becoming the first Australian Open defending men's champion to lose in the first round since his current coach, Carlos Moya, managed to beat Boris Becker a quarter of a century ago.

Still, this was not a vintage performance by Nadal, who came into Monday's matchup against 21-year-old Jack Draper with an 0-2 record in 2023 and six losses in his past seven outings overall. After nearly two hours of so-so play, Nadal found himself even at a set apiece.

He appeared to be pulling away, taking advantage of his opponent's bout with cramps on an afternoon with the temperature at about 85 degrees Fahrenheit (30 Celsius), when suddenly Draper went up by a break in the fourth set.

From there, though, Nadal would not drop another game, beginning his pursuit of a record-extending 23rd Grand Slam championship with a 7-5, 2-6, 6-4, 6-1 win that took more than 3 1/2 hours in Rod Laver Arena.

"I need a victory, so that's the main thing," Nadal said. "Doesn't matter the way." That's good, then, because the 36-year-old from Spain was not in peak form. All in all, it was a bit of a struggle. He tried to put a silver-lining spin on things, nonetheless, given his recent track record and knowing that he tore an abdominal muscle twice in the past six months.

"I was humble enough to accept that (there were) going to be a little bit of ups and downs during the match," Nadal said. "(That's a) typical thing when you are not in a winning mood." Both men are left-handers, but that is pretty much where the similarities end, whether in terms of style or age or experience or accomplishments.

Nadal, who is seeded No. 1 because top-ranked Carlos Alcaraz is sidelined with an injury, is appearing in his 67th Grand Slam tournament. Draper, ranked a career-best No. 38 this week, was making his fourth trip to a major and his best showing was getting to the third round at the US Open last September.

Draper also has faced problems dealing with steamy conditions: In his ATP Tour debut at the Miami Open in March 2021, he collapsed on court and needed to stop playing after one set.

"Real honor to play against him, someone I've idolized growing up. To go toe-to-toe with him on a big court like that is special," Draper said. "I can take away the fact that my tennis is getting closer and closer. And physically, I'll be first to say I'm still a work in progress."

This time, signs of trouble showed up early, and Draper was treated by a trainer during changeovers. Later, he massaged his right thigh between points.

Nadal, not surprisingly, wore Draper down from the baseline, engaging in exchanges before finding an opening to yank a big forehand this way or that.

"When you win matches, you are more relaxed," Nadal said. "You are more confident." His next opponent will be Mackie McDonald, a past NCAA champion at UCLA who won an all-American matchup against Brandon Nakashima that lasted 4 hours by a 7-6 (5), 7-6 (1), 1-6, 6-7 (10), 6-4 score.

The No. 1-seeded woman, Iga Swiatek, followed Nadal into Laver for the night session and found herself in a tight second set before reeling off the last four games to eliminate 69th-ranked Jule Niemeier 6-4, 7-5.

Americans Jessica Pegula, Coco Gauff and Danielle Collins, the 2022 runner-up at Melbourne Park, also reached the second round with straight-set victories Monday, and 2017 US Open finalist Madison Keys won in three sets.

Others advancing included 2019 US Open champion Bianca Andreescu, 2021 US Open champion Emma Raducanu and sixth-seeded Maria Sakkari, while two-time Australian Open champion Victoria Azarenka got past 2020 winner Sofia Kenin 6-4, 7-6 (3).

There were plenty of other major titlists on the packed Day 1 schedule, with Petra Kvitova, Elena Rybakina, Jelena Ostapenko and Barbora Krejcikova among the winners. But three-time Slam champ Stan Wawrinka bowed out with a 6-7 (3), 6-3, 1-6, 7-6 (2), 6-4 loss to Alex Molcan.

The biggest surprise of the day came off the court: the withdrawal of Wimbledon finalist Nick Kyrgios, who needs surgery on his left knee.

"I'm devastated, obviously," said Kyrgios, a 27-year-old from Australia who won the men's doubles championship at Melbourne Park a year ago.

Men who moved on included No. 3-seeded Stefanos Tsitsipas, No. 6 Felix Auger-Aliassime, No. 10 Hubert Hurkacz, No. 16 Frances Tiafoe and No. 20 Denis Shapovalov. Daniil Medvedev, the 2021 US Open champion and the runner-up in Melbourne the past two years, breezed past Marcos Giron of the US 6-0, 6-1, 6-2 at night.

The No. 3-seeded Pegula overwhelmed Jaqueline Cristian of Romania 6-0, 6-1 in just 59 minutes, No. 7 Gauff overcame a second-set wobble to beat Katerina Siniakova 6-1, 6-4, and No. 13 Collins had her left knee treated and taped up while defeating Anna Kalinskaya 7-5, 5-7, 6-4.

Pegula and Gauff could meet in the semifinals; Collins could play Swiatek in the fourth round.

"Today is just one of those days everything was working," said Pegula, a quarterfinalist in Melbourne each of the past two years. "Always feels good when you win a match like that. I think when those days come you just kind of take it and don't complain and don't critique. You kind of just move on to the next one." AP freelancer Simon Cambers contributed to this report.

                                                                                                              AP