Serena Williams says her Australian Open quarterfinal collapse to Karolina Pliskova was a learning experience.

The 23-time Grand Slam champion squandered a 5-1 lead and four match points in the decisive set. Williams, who was hit with a foot fault call that nullified an ace on match point also sprained her ankle on her first match point, then never won another point on serve.

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Visiting Good Morning America today, Serena told host Robin Roberts, she's learned lessons from both her trip down under and her return after giving birth to her first child, daughter Alexis Olympia, in September of 2017.

"I took some time off to have a baby, which is like the best thing I've ever done in my life," Serena told Robin Roberts of GMA. "And you lose little things and this has only been 10 months so I've only been back for 10 months and it's really been miraculous, to be honest.

"I've learned little things that I used to do that I have to be like 'Oh I remember that,' so I won't do that again. I learned that when I'm in the lead, I'm a closer. I'm really known to be a closer and so it's little moments like that you just don't think about because you spend so long away and you really don't get that match play and match experience. So everything I've done in 10 months has already been crazy. It's still little lessons that I'm learning."