But Barty, whose best showing at a major is the US Open fourth round last year, has welcomed the pressure, saying this year's career plan was always to "go deep into Slams".
Until now, that is. In her on-court interview, she saluted her former cricket team and said she'd watched on TV the previous day as they qualified for the national final.
She doubted she would ever make it back after forced out of the game for a period in 2017 to recover from hand surgery in the wake of the attack. There was barely a dry eye in the arena. Another severe test now awaits, with Kvitova showing her pedigree by taking down highly promising American teenager Amanda Anisomova for the loss of only three games.
"It is another challenge and an opportunity for me to play my best tennis", added Barty. I'm a bit sorry that I beat her.
"She came out with a really solid game plan against me".
Since her return to the majors at the French Open in 2017, she has had two first-round exits, two second-round losess, two in the third.
ASH Barty's Australian Open dream lives on after the Queenslander escaped Maria Sharapova's clutches to storm into Melbourne Park's quarter-finals. I still, as I said, still have to take care of the shoulder. "But, yeah, it took me a while, for sure".
"When I'm counting the years, it's pretty long", Kvitova said. I'm really embracing it.
"She's got 10 great years ahead of her if she stays healthy".
Stephens, the 2017 U.S. Open victor, started strongly by gaining a 4-1 advantage but her Russian opponent got the break back before the 25-year-old American won the set via a tiebreaker.
The difference is fewer nerves, more job satisfaction and more freedom.
She officially returned to the sport in June, 2016, and worked hard to get her ranking back.
But despite failing to progress beyond the first round in any of the Slams, Collins believes she has what it takes to compete with the best.
Collins has a 5-5 career record in Grand Slam matches. Sunday morning, she kissed her husband and four kids goodbye, drove from their home in Grand Rapids, Minnesota, to Minneapolis and hopped a flight to Melbourne.
Games went on serve until Kvitova broke Barty to lead 5-4 and she served out the match to win in one hour and eight minutes. "I do have a different mindset than I had those years when I won", said Kvitova. Kvitova, 183cm and left-handed, comes by her potent serve more naturally. As far as a victor is concerned, I am going to pick Danielle Rose Collins to win this match.
Kvitova will start this match as the favourite to win - this is a given. "Looking forward to the next match". "He serves well. Very quick forehand", said the second seed, who has not dropped a set so far.