MELBOURNE       -        Plenty was going badly for Coco Gauff in the second round of the Australian Open. The double-faults kept coming Wednesday, nine in all. The deficits, too: First, she dropped the opening set against 74th-ranked Sorana Cirstea. Then, after forcing a third, Gauff fell behind by a break, ceding 14 of 16 points with a series of mistakes. Later, after getting even at 3-all, Gauff was a mere two points from a loss.

None of that mattered. As she keeps showing, over and over, Gauff is not a typical 15-year-old. Not a typical tennis player, either. And by getting past Cirstea 4-6, 6-3, 7-5 in a little more than two hours thanks to a more aggressive approach in the late going, she now has set up yet another Grand Slam showdown against Naomi Osaka. “I kind of felt the momentum changing,” Gauff said about turning things around against Cirstea. “I knew I had to keep pressing.”

Less than five months after their memorable meeting at the U.S. Open -- Osaka won that one in straight sets, then consoled a crying Gauff on court and encouraged her to address the spectators -- the two will face each other again. Like that time, Osaka is the major’s reigning champion and Gauff is making her debut at the tournament.

Other winners on day 3 included Serena Williams — 6-2, 6-3 against Tamara Zidansek in a match that finished with the Rod Laver Arena retractable roof closed because of rain — No. 1 Ash Barty, 2018 Australian Open champion Caroline Wozniacki and two-time major champion Petra Kvitova, the runner-up to Osaka in Australia a year ago.

Defending men’s champion Novak Djokovic required all of 95 minutes to breeze past Japanese wild-card entry Tatsuma Ito 6-1, 6-4, 6-2, while Roger Federer had a similarly easy time, beating 41st-ranked Filip Krajinovic of Serbia 6-1, 6-4, 6-1. While Federer had the usual Grand Slam day off between matches, Krajinovic’s first-round contest was postponed by showers and so he didn’t have the proper rest after a five-set win Tuesday.“I do feel a little bit sorry,” said Federer, who now meets Australia’s John Millman, who surprised him in the fourth round of the 2018 U.S. Open.

Gauff was not at her very best on a windy afternoon against Cirstea but managed to figure her way out of trouble repeatedly. Gauff demonstrated plenty of grit, yes, and also enthusiasm, pumping herself up by shaking a fist and yelling, “Come on!” after most of her successful points down the stretch. All the while, Gauff was supported by a Melbourne Arena crowd that chanted, “Let’s go, Coco! Let’s go!”

Her father, Corey, was animated in the stands, too, except when he was squeezing his eyes shut at critical moments. There were several of those for his precocious daughter, who was ranked only 313th last year when she became the youngest player in history to qualify for Wimbledon, then wound up beating Williams there en route to the fourth round.