Cori “Coco” Gauff makes a backhand return to Sorana Cirstea during their second-round singles match at the Australian Open in Melbourne, Australia, today. (AP photo)

The double-faults kept coming today, 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, 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.

Cori "Coco" Gauff of the U.S. celebrates after defeating Romania's Sorana Cirstea during their second-round singles match at the Australian Open in Melbourne, Australia, today. (AP photo)

Other winners on Day 3 included Serena Williams — 6-2, 6-3 against Tamara Zidansek; No. 1 Ash Barty, 2018 Australian Open champion Caroline Wozniacki and two-time major champion Petra Kvitova.

Defending men’s champion Novak Djokovic required 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.