Speaking shortly after losing 6-4, 6-7 (6-8), 4-6 to Puerto Rican world No.58 Monica Puig, the 33-year-old Queenslander said she had "gone over match point about a hundred times already in the past 45 minutes".

Having served superbly and cleverly used her sliced backhand to advantage, Stosur looked in command at 4-3 in the second set, before dropping her serve to send the set to a tie-breaker.

The crowd favourite fought hard and served well to set up match point with a 6-5 lead, and was within touching distance when Puig's first serve was a fault. But after an 11-shot rally Stosur pushed a forehand long. The Puerto Rican went on to take the second set and looked in command, winning the deciding set 6-4.

Having tormented herself about whether she should have "gone for a bit more, should I have been a bit more aggressive" on match point, Stosur accepted she had simply been outplayed by Puig, who changed up her tactics in that rally.

"I was as close as you can get without winning," Stosur lamented.

The only Australian player to have won a major in the past 15 years, Stosur has had a patently disappointing career in Melbourne Park. Competing in her 16th Australian Open, she has never made it beyond the fourth round and has now departed six times in the first round, losing to such middling players as Sorana Cirstea (2012), Kristyna Pliskova (2016) and Heather Watson last year.

But when asked about her struggles in her home grand slam event, Stosur assured the media "I don't really think about it".

"Everyone else makes a bigger deal about it than I do, personally. Look I was one point away and then I'd be in the second round if I'd won one more point. Unfortunately that's the way it goes sometimes. For whatever reason it won't happen for me, so I'll come back next year and do it all over again."

Desperate to avoid another early exit, Stosur had taken to the court with "courage" and "kind" written on her left wristband. She explained that they were two aspects of her game she was determined to focus upon.

"Just to have courage to do what I should be doing out there, and not to be beating myself up too much. Just to try to be a bit kinder to myself," Stosur explained.

"They're things that I've been working on throughout my game, not the forehand and backhand side of things."

She said that for the most part she felt she did well in those two of the aspects of her game.

Stosur, now ranked 41 in the world, won the 2011 US Open against Serena Williams, came very close at the 2010 French Open and made the semis at Roland Garros 18 months ago. But mental doubts seem to plague her at home.

Pressed about why her Australian Open record was so moderate, Stosur said: "I just struggle on these hard courts a bit ... if I could play on an American hardcourt with different balls I'd probably be a lot happier."

Puig, who had never lost in the first round of the Australian Open in four previous outings, also had her own doubts to overcome.

In 2016, she won Olympic gold, the first for Puerto Rico in 68 years of competing, and was ranked as high as 27, but has since said she felt "cursed" by the medal. She says perspective came after she returned to her beloved island after it had been battered by hurricanes in September, after which she raised hundreds of thousands of dollars and handed out emergency supplies during a humanitarian trip with former world No.1 Maria Sharapova.

Stosur said she would now focus on playing mixed doubles here with fellow Australian Sam Groth, and had set herself a goal to regain one of the 32 seeding slots ahead of the French Open in June,

"And I guess I'll come back next year and try and have a great Aussie Open," she said. "It's not always necessarily my happiest moments, but if I can do that, I'll be pretty damn happy."

Unseeded local Olivia Rogowska has become the first Australian woman through to the second round of the Australian Open, outlasting compatriot Jaimee Fourlis in three sets. The unseeded 26-year-old, ranked 168 in the world, battled for a 6-2, 6-7 (3-7) 6-2 victory in a two-hour, all-Australian affair on show court 3.