Rafael Nadal won his first match back from a year-long injury layoff when he beat former US Open champion Dominic Thiem at the Brisbane International on Tuesday, calling it an "emotional and important day".
The 22-time Grand Slam winner looked in superb touch with a clinical 7-5, 6-1 victory over the Austrian in front of a full house at Pat Rafter Arena.
He will now play Jason Kubler in the second round after the Australian wildcard progressed when Aslan Karatsev was forced to withdraw injured with the scores locked at one set apiece.
The 37-year-old Spaniard had not played singles since a second-round loss at the Australian Open last year, undergoing two rounds of hip surgery.
"Today, honestly, is an emotional and important day for me after probably one of the toughest years of my tennis career, without a doubt," he said.
"To have the chance to come back after a year and play in front of an amazing crowd, and play I think at a very positive level for the first day is something that makes us feel proud."
The former world number one did concede the result could have been very different.
"I know I have been practising okay in the last week, practising I think at a positive level," Nadal said. "I'm talking with my hand on my heart and being very honest with all of you.
"You really at the end hope that you're going to play at this level, but inside yourself you know that it can be a disaster, and that, of course, worried me."
The long layoff raised fears that his career could be over, but Nadal said this week he was always determined to make it back for the 2024 season.
He conceded before the match there was "a high percentage" that it would be his last season, but left the door open to play on should his body hold up.
"I missed being healthy, I missed feeling competitive and to play in front of full crowds like this," he said courtside after beating Thiem in 89 minutes.
Nadal spent time at his academy in Kuwait to prepare for the Australian summer and trained there with fast-rising French teen Arthur Fils.
He looked like he had never been away as he lost only six points on serve throughout the match and made few unforced errors in an almost perfect display against a quality opponent.
Former world number three Thiem, who has had injury concerns of his own, came through qualifying to make the main draw and matched Nadal throughout the first set.
But at 6-5 and with the set looking certain to go to a tiebreak, Nadal stepped up the pressure on Thiem's serve, forcing a series of errors and eventually winning the set when a Thiem forehand sailed long.
Nadal then seized the advantage, holding his serve to love and then breaking Thiem to take a 2-0 lead in the second set.
The Austrian's head then seemed to drop as Nadal lifted even further, wrapping up the match easily.
"I think the first set was very equal, both of us serving well and then I was able to have that break for 6-5," he said.
"I know Dominic has been going through hard times with injuries too, so happy to see him on court, wish him all the very best for the season."
Earlier, fifth-seeded American Sebastian Korda and Argentinian sixth seed Sebastian Baez both crashed out.
Germany's Yannick Hanfmann downed Korda 7-5, 6-4 while Baez lost to Lukas Klein, with the Slovakian qualifier winning 4-6, 6-3, 6-4.
In the women's draw, former world number one Victoria Azarenka came back from second set jitters to see off Russia's Anna Kalinskaya 6-1, 7-6 (10/8), while Sofia Kenin, a former Australian Open winner, was stunned by Australian wildcard Arina Rodionova 7-5, 7-6 (9/7).
