Australian Open 2019: Roger Federer, Angelique Kerber's Losses Highlight Sunday

Roger Federer and Angelique Kerber exited the 2019 Australian Open on Sunday after they suffered upsets at the hands of Stefanos Tsitsipas and Danielle Collins, respectively.

Tsitsipas battled back from a set down to beat Federer in a hard-fought four-set thriller, while Collins eased to a surprisingly straightforward win over No. 2 seed Kerber.

Sloane Stephens also fell victim to an upset, allowing Anastasia Pavlyuchenkova to come back to win in three sets.

Rafael Nadal had no problems getting past Tomas Berdych in straight sets in his outing, but Marin Cilic and Grigor Dimitrov saw their campaigns come to an end at the hands of Roberto Bautista Agut and Frances Tiafoe, respectively.

Ash Barty continued her run as she came from behind to beat Maria Sharapova in three sets, while No. 8 Petra Kvitova made short work of Amanda Anisimova.

Men's Singles Results

(2) Rafael Nadal bt. Tomas Berdych, 6-0, 6-1, 7-6 (4)

(14) Stefanos Tsitsipas bt. (3) Roger Federer, 6-7 (11), 7-6 (3), 7-5, 7-6 (5)

(22) Roberto Bautista Agut bt. (6) Marin Cilic, 6-7 (6), 6-3, 6-2, 4-6, 6-4

Frances Tiafoe bt. (20) Grigor Dimitrov, 7-5, 7-6 (6), 6-7 (1), 7-5

Women's Singles Results

Danielle Collins bt. (2) Angelique Kerber, 6-0, 6-2

(8) Petra Kvitova bt. Amanda Anisimova, 6-2, 6-1

(15) Ash Barty bt. (30) Maria Sharapova, 4-6, 6-1, 6-4

Anastasia Pavlyuchenkova bt. (5) Sloane Stephens, 6-7 (3), 6-3, 6-3

Recap

When Tsitsipas took eight minutes and had to save two break points to hold serve in the first game of his match with Federer, it seemed the 20-year-old would be in for a long evening at the hands of the defending champion.

Indeed he was, but it was because he gave as good as he got during their three hours and 45 minutes on court.

Federer had 12 opportunities to break Tsitsipas over the course of the match, including four set points in the second set, but failed to take a single one.

The Greek's resistance was superb:

Unlike his opponent, opportunities to break were few and far between for Tsitsipas, but when they did he was far more clinical in taking them, which ultimately proved the difference.

Federer conceded Tsitsipas had been the better player, per Metro's George Bellshaw:

Breaks were much easier to come by in Stephens' clash with Pavlyuchenkova. The American broke the Russian four times, but lost seven games on her own serve.

There aren't many players still representing the United States in Melbourne this year:

Unexpectedly, Collins is still flying the flag for the Americans. She swept Kerber aside with remarkable ease, embarrassing the three-time Grand Slam winner with a bagel in the opening set:

The second set went by almost as quickly, as Collins continued her domination of the proceedings.

The American had never won a match at a Grand Slam prior to this campaign, but she'll now compete in the quarter-finals in Melbourne having beaten three seeded players in her first four matches.

Like Collins, Nadal barely broke a sweat in his match on Sunday, and his first set was just as one-sided as Collins' had been, per Ben Rothenberg of the New York Times:

The Spaniard won 12 of the first 13 games before Berdych managed to make it anything resembling a contest, but the third-set tiebreaker nevertheless went Nadal's way.

His opponent in the next round, Tiafoe, had a much more challenging tie as he overcame 20th seed Dimitrov.

The American cut an emotional figure after the match:

He'll be joined in the next round by Bautista Agut, who continued his impressive run through the tournament in five sets against Cilic.

The Spaniard knocked out last year's runner-up, having previously overcome Andy Murray, John Millman and 10th seed Karen Khachanov in his first three matches.