Emma Raducanu shone at a grand slam again as she marked her Australian Open debut with victory in the battle of the US Open champions against Sloane Stephens.
The 19-year-old has found wins hard to come by since her extraordinary success in New York in September but, back on the big stage, Raducanu came up with the right formula again to claim a 6-0 2-6 6-1 victory.
She lost just four points in a startling first set that admittedly was woeful from Stephens before the American hit her stride in the second.
That set up a first ever decider at this level for Raducanu, and she could not have handled it any better, keeping her cool and striking the ball with confidence to clinch victory after an hour and 45 minutes.
Both players went into the match undercooked - Raducanu after a battle with Covid-19 and Stephens following her wedding to footballer Jozy Altidore on New Year's Day.
Raducanu won only one game against Elena Rybakina in Sydney last week having just returned to full training and it was hard to know what to expect from her here.
What transpired in a remarkable 17-minute first set was that Raducanu had found her sharpness while Stephens looked like she was still on honeymoon.
Stephens made error after error, allowing Raducanu the freedom to go for winners, which she made with aplomb.
Stephens looked a star in the making when she reached the semi-finals here nine years ago but her career had been more troughs than peaks prior to a brilliant run to the title in New York in 2017.
The last few years have brought a few more highlights mixed with many underwhelming results but Stephens remains a fluent ball striker and sublime mover, and someone who often finds her best on the big stage.
Her scalps at the slams last year included Karolina Pliskova, Petra Kvitova, Madison Keys and Coco Gauff, and she set about turning things around at the start of the second set.
She was helped initially by a dip in level from Raducanu, but it did not appear to bode well for the teenager that, even when she found her range again, the fleet-footed Stephens still had the answers.
Raducanu knew how important the start of the deciding set was and she gave a gritty fist pump after holding serve in the first game.
If there was evidence here of Raducanu's greenness, there was also plenty of the prodigious ball-striking that wowed fans and players alike at Wimbledon and the US Open, and the competitive steel that was just as important in her success.
She broke Stephens to lead 2-0 and then overcame an embarrassing moment when she thought she had won the next game only to be told by the umpire that it was in fact 40-15.
Stephens' heart for the fight began to ebb away and, although she avoided a second bagel, a netted backhand gave Raducanu victory on her third match point.
The big names prevailed on Tuesday but Australian veteran Sam Stosur stole the show in her final tournament.
The 37-year-old, who defeated Serena Williams to win the US Open more than a decade ago, announced ahead of the event that this will be her final appearance as a singles player.
Now ranked 487, Stosur had not won a singles match since the first round here last year, but she delighted her home fans by coming from a set down to defeat Robin Anderson 6-7 (5) 6-3 6-3.
“That’s kind of been the focus all along since I knew this was going to be my last event, was to play how I want to play, go out and enjoy it, pretty much do what I did today,” said Stosur, who struggled with the pressure at Melbourne Park in her prime and has never made it past the fourth round.
“I couldn’t really ask for much more. It was just great to get out there and play that sort of tennis in that sort of match out there with that crowd.”
Second seed Aryna Sabalenka came into the tournament winless this season and in the middle of a serving crisis.
She hit 12 doubles faults against Australian Storm Sanders but recovered from a set and 3-1 down to win 5-7 6-3 6-2.
Sabalenka credited her victory to former Wimbledon champion Mark Philippoussis, who she revealed reached out to her and offered some serving tips.
The Belarusian said: “He was in Adelaide and after my second match he just wrote me, like, ‘Well, girl, just stop thinking a lot on your serve. If you have some time today… we can go out on the court, I can help you.’
“And I think at 9.0pm or 8.0pm, we went on court and we served a lot and he gave me some tips about what should I focus on during the game when I’m struggling with my serve. I’m really thankful to him for this help because that’s what helped me today in the match to just survive there.”
Third seed Garbine Muguruza was a 6-3 6-4 winner over young Frenchwoman Clara Burel while seventh seed Iga Swiatek won 11 games in a row to beat Harriet Dart 6-3 6-0 and in-form sixth seed Anett Kontaveit saw off Katerina Siniakova 6-2 6-3.
Simona Halep is also through after a 6-4 6-3 win over Magdalena Frech but another former finalist, 20th seed Petra Kvitova, continued her poor form, going down 6-2 6-2 to Sorana Cirstea, while former champion Angelique Kerber was beaten 6-4 6-3 by Kaia Kanepi.
Australian wild card Maddison Inglis pulled off arguably the result of the day, beating US Open runner-up Leylah Fernandez 6-4 6-2.
The Canadian said: “Today was just not a good day. Too many mistakes. I’ll give credit to Maddie. She played a great match from beginning to end. I, unfortunately, did not find the right solutions to get back in it and to make it to a third set. It happens.”