Australian Open 2019 Results: Winners, Scores, Stats from Sunday's Bracket

Sunday was a day of upsets in the Australian Open.

With the defending men's champion bowing out early and one of the top women's contenders failing to advance, Sunday was a shocking day on the Melbourne hard courts. Below, we'll break down the results.

Men's Results

No. 14 Stefanos Tsitsipas def. No. 3 Roger Federer: 6-7, 7-6, 7-5, 7-6

No. 2 Rafael Nadal def. Tomas Berdych: 6-0, 6-1, 7-6

No. 22 Roberto Bautista Agut def. No. 6 Marin Cilic: 6-7, 6-3, 6-2, 4-6, 6-4

Frances Tiafoe def. No. 20 Grigor Dimitrov: 7-5, 7-6, 6-7, 7-5             

Women's Results

No. 8 Petra Kvitova def. Amanda Anisimova: 6-2, 6-1

No. 15 Ashleigh Barty def. No. 30 Maria Sharapova: 4-6, 6-1, 6-4

Anastasia Pavlyuchenkova def. No. 5 Sloane Stephens: 6-7, 6-3, 6-3

Danielle Collins def. No. 2 Angelique Kerber: 6-0, 6-2

Recap

Nothing was more shocking on Sunday than Federer's loss to the 20-year-old Tsitsipas, ending his hopes of claiming a seventh Australian Open title and a third straight at the tournament. 

"I have massive regrets tonight," Federer said after the match, per Simon Cambers of ESPN.com. "I might not look the part, but I am. I felt like I have to win the second set. I don't care how I do it, but I have to do it. Cost me the game tonight."

Tsitsipas was obviously singing a different tune. "I'm the happiest man on the Earth right now," he said.

Tsitsipas deserved the win, smashing 20 aces and 62 winners while limiting his unforced errors (36, compared to 55 for Federer). He also impressed his legendary opponent, with Federer saying:

"About Stefanos, I think he's definitely done a really nice job now the last year and a half. I mean before that, too, obviously. But beating Novak [Djokovic] in Toronto, the likes of [Kevin] Anderson and [Alexander] Zverev, now me here. That's what you need to do to get to the next level. He's doing that. It's really nice for him."

That wasn't the only upset in the men's draw, however, with both Cilic and Dimitrov falling. Tiafoe's win was all the more shocking, considering it was the first time he's reached the fourth round in a Grand Slam.

"It means the world. I worked my ass off, man," he said, per Alyssa Roenigk of ESPN.com. "I told my parents 10 years ago I was going to be a pro, I was going to change their lives and my life, and now I'm in the quarters of a Slam. I can't believe it."

Tiafoe's reward for reaching his first Grand Slam quarterfinal is a date with Nadal. 

The upsets were prevalent on the women's side, too, with No. 2 overall seed and 2016 Australian Open champ Kerber falling to Collins.

"I may not have won a Grand Slam match before this week, but I gotta tell you, I think it's gonna keep happening," Collins said after pulling off an improbable but dominant upset. 

Collins won 65 percent of both her first- and second-serve points, converting six of seven break points and winning seven of 10 net points. The American bested Kerber in winners, 29-6, and completely controlled the match.

Stephens, meanwhile, was the second top-five seed to drop in the women's draw Sunday, falling to Pavlyuchenkova despite winning the first set.

Then there was Barty, who overcame losing the first set to defeat Sharapova and secure a matchup against the dangerous Kvitova in the quarters.

"Sitting down with my team late last year, it was one of the goals we set out—that we wanted to go deep into Slams," she said, per Roenigk. "I feel like that was the next step for me. It's amazing that it is happening in Australia in front of the best crowd in the world. There is absolutely nothing better."