- It was Murray's 49th win in an Australian Open singles match, moving him into fifth-place all-time.
- "I think there's things in my game I can do better," said Murray, who lost the 2010 final.
- Raducanu was scheduled to play later Tuesday against 2017 US Open champion Sloane Stephens.
Five years and five long sets later, five-time Australian Open runner-up Andy Murray finally has won another match at the season-opening Grand Slam tournament.
The former No 1-ranked Murray, playing thanks to a wild-card invitation as he continues his career comeback from hip operations and thoughts of retirement, beat 21st-seeded Nikoloz Basilashvili 6-1 3-6 6-4 6-7(5) 6-4 on Tuesday to reach the second round at Melbourne Park.
He lost a five-setter in the first round in 2019 — a match he, and everyone else, thought might have been his last in Australia — after missing the 2018 edition with an injury. He missed the 2020 tournament with a pelvic injury and last year's event because of COVID-19.
"It's been a tough three, four years. Put in a lot of work to get back here," Murray said in his post-match TV interview at John Cain Arena, which was formerly known as Hisense and is parochially referred to as the People's Court.
"I've played on this court many times, the atmosphere is incredible. This is the one where I thought I'd played my last.
"Amazing to be back, winning a five-set battle like that. Couldn't ask for more." Murray beat Basilashvili in a three-hour three-setter last week in Sydney, where he reached the final of the tuneup tournament. This one went almost four hours.
When the 34-year-old Murray clinched it on his third match point, he turned to the back of the court, closed his eyes and pumped his fists to celebrate.
After walking over to his courtside chair and dropping his racket, he returned to the court, punched the air and yelled "Let's go!"
It was Murray's 49th win in an Australian Open singles match, moving him ahead of Andre Agassi and Ivan Lendl into fifth-place all-time.
Match win No 50 is the immediate priority.
"I think there's things in my game I can do better," said Murray, who lost the 2010 final to Roger Federer and four others to Novak Djokovic.
"Would love to have a deep run here, if possible.
"It's something I've not had in one of the Slams since I've come back from the injury, and it's something that's motivating me."
Murray's wasn't the only dramatic five-setter that finished in the early evening on Day 2.
Ninth-seeded Felix Auger-Aliassime fended off Emil Ruusuvuori 6-4 0-6 3-6 6-3 6-4, and Maxime Cressy overcame 20 double-faults to upset fellow American and No 22-seeded John Isner 7-6(2) 7-5 6-7(4) 6-7(4) 6-4.
Second-seeded Daniil Medvedev, one of the biggest potential beneficiaries of Djokovic's deportation, had a much more routine first round.
Nine-time champion Djokovic was already back in Serbia — two days after losing his legal challenge to stay in Australia despite being unvaccinated against COVID-19 — when Medvedev went into Rod Laver Arena for a 6-1 6-4 7-6(3) win over Henri Laaksonen.
Aiming to be the first man in the Open era to win his second major title in the very next Grand Slam appearance after his first such trophy, Medvedev joined No 5 Andrey Rublev, No 11 Jannik Sinner, No 13 Diego Schwartzman, No 15 Roberto Bautista Agut and No 27 Marin Cilic in the second round.
Nobody has dominated in Melbourne like Djokovic, who is unbeaten in the 18 combined semifinals and finals he's reached at the Australian Open, including last year's victory over Medvedev for the title.
But Medvedev avenged that with his breakthrough major title at the US Open, where his victory meant Djokovic's bid for a calendar-year Grand Slam finished one win short.
"I like pressure," Medvedev said. "Always want to do better than I did last year, (but) it's not going to be easy."
That's something Leylah Fernandez has had to confront.
The 19-year-old Canadian lost 6-2 6-4 to 133rd-ranked wild-card entry Maddison Inglis in her first Grand Slam match since her runner-up finish at the US Open.
Fernandez made 30 unforced errors, dropped her serve three times and hit only eight winners on 1573 Arena against Inglis, who converted her third match point to complete her very first win in the main draw of a major.
The venue and the vibe were a long way from her run to the final against Emma Raducanu at Flushing Meadows.
Raducanu was scheduled to play later Tuesday against 2017 US Open champion Sloane Stephens.
Third-seeded Garbiñe Muguruza, meanwhile, kept a perfect streak intact when she won her first-round match at the Australian Open for the 10th straight time, beating No. 77-ranked Clara Burel 6-3 6-4.
Muguruza, a two-time major champion who was the 2020 runner-up in Australia, next plays French veteran Alize Cornet. Sixth-seeded Anett Kontaveit, runner-up to Muguruza at least year's WTA Finals, had a 6-2 6-3 win over Katerina Siniakova. Seventh-seeded Iga Swiatek, the 2020 French Open champion, opened with a 6-3, 6-0 win over 123rd-ranked British qualifier Harriet Dart.
Also advancing were 2021 French Open finalist Anastasia Pavlyuchenkova and Simona Halep, a former No 1 and a two-time major champion who reached the 2018 final at Melbourne Park.
No 19 Elise Mertens beat Vera Zvonareva 6-4 7-5 and 2011 US Open champion Sam Stosur rallied to beat Robin Anderson 6-7(5) 6-3 6-3 to start her 20th — and last — Australian Open singles campaign.
Two-time Wimbledon champion Petra Kvitova lost to Sorana Cirstea of Romania for the second straight year, this time 6-2 6-2 in the first round.