WTA Insider Courtney Nguyen | Which Hollywood legend tweeted Kristyna Pliskova as Svetlana Kuznetsova survived a Melbourne marathon? This and more from Day 5 at the Australian Open.
WTA Staff

MELBOURNE, Australia - On Day 5 of the Australian Open, the favorites took care of business. The two surprises of the day came from Anastasia Pavluchenkova knocking out No.11 seed Elina Svitolina and Sorana Cirstea continuing her good form to beat Alison Riske and advance to her first Round of 16 at a Slam since the 2009 French Open.

Here's what you missed:

The Top Half Round of 16 is set for Sunday.

No.1 Angelique Kerber vs. No.35 CoCo Vandeweghe
No.78 Sorana Cirstea vs. No.7 Garbiñe Muguruza
No.116 Mona Barthel vs. No.17 Venus Williams
No.27 Anastasia Pavlyuchenkova vs. No.10 Svetlana Kuznetsova

Mona Barthel's long road back.

The German's talent has never been a question. With a fluid backhand that can take the ball down the line with remarkable precision and disguise, the 26-year-old hit a career-high of No.23 in 2013. But she came into Melbourne having to qualify for the main draw, with a ranking that plummetted to No.116 after an undiagnosed illness derailed her 2016 season.

"Nobody knew what it was exactly," Barthel said. "Starting around here last year when I got back home I just couldn't do anything. Walking 100 meters was totally exhausting for me. It was a really tough time. Tennis wasn't really a part of it, I was just trying to get back to live a normal life. I really didn't know if I could return.

"It was a tough year for me. I was really sick for a long time. It took me a lot of time to come back and feel physically good again. I think since December I felt a lot better and could practice a lot more and get the hours on the court. I'm just physically much fitter than I was before and that helps me mentally because I know I can play the long rallies and go for three sets.

"It was mentally tough because if you don't have a diagnosis you don't know if it's coming back. It was tough sometimes on court. I just didn't know where my body was, if I could trust it again. But it's much better now."

Barthel needed all her reserves to get past another solid performance from Ashleigh Barty, coming back from a break down in the third to win 6-4, 3-6, 6-3. The win puts Barthel into her first Round of 16 at a Slam where she'll face Venus Williams.

"She's a great player. If she's on, she's playing unbelievable. But I won six matches in a row. Nothing is impossible."

Svetlana Kuznetsova plays another marathon in Melbourne.

It was six years ago that Kuznetsova played her part in setting the record for the longest women's match at a Slam, eventually succumbing to Francesca Schiavone here in Melbourne in 4 hours and 44 minutes. The No.9 seed didn't have to go that far this time, but she needed 3 hours and 36 minutes to get past Jelena Jankovic 6-4, 5-7, 9-7. Kuznetsova rallied back from 0-3 down in the final set to nip Jankovic in the end.

CoCo Vandeweghe swags past Eugenie Bouchard.

In the most anticipated match of the day, Vandeweghe came back from a break down in the third set to beat Bouchard 6-4, 3-6, 7-5 in a top-quality battle between two big hitters. The win puts Vandeweghe into her first Round of 16 at a hard court major and she'll get a chance to pull off the upset over No.1 Angelique Kerber on Sunday.

One thing is for sure: Vandweghe will not be short of confidence. The American was asked whether her win over Bouchard ranked high on her list of career victories and Vandeweghe dismissed the idea.

"Actually, not that high now that I think about it," she said, smiling. "I think there are different moments in my career that I have, my short career, that I enjoy, different wins for different reasons.

"I think probably my favorite match that I won -- well, I probably have to say tournament, is probably my first WTA title would be my favorite. Then after that, I had a really good run at Montreal where I beat Jankovic and Ivanovic back to back, and that was the first time I ever beat two -- I believe they were top 10, both of them, at the time, first time I had ever done that.

"So this one isn't that high for me. It was kind of expected, in my mind, to get the win and to get the victory and to move a step closer to achieving what I want to achieve for this year and also this tournament."

Venus Williams doesn't age.

The 36-year-old has now made the second week at four consecutive Slams and has done so in seven of her last nine majors. On Friday she lost just one game to Duan Ying-Ying, sealing the match in under an hour.

Kristyna Pliskova has a surprising admirier.

The Czech couldn't do much against Kerber, losing 6-0, 6-4 in 55 minutes. But she certainly caught one Gladiator's attention:

Quote of the Day: "It wasn't a horrible trip."

Bouchard leaves Australia with a lot of positives, having found some consistent form to make the Sydney semifinals and come within a few games of the Round of 16 here.

"Obviously, deep down, always expect more, but, you know, I couldn't expect too much, considering I trained for a month, and it's the first, you know, really good training I got in a while, first time I got a good break in a while, first time I trained well in a while," she said.

"It's kind of like a restart process. I can't expect too much at the beginning. It wasn't a horrible trip."

The Barty Party is over.

It was a great tournament for Barty, who will jump to around No.150 after the tournament. "I think if you would have asked me 12 months ago if I was going to be in the third round of the Australian Open, I would say, Mate, you're kidding," Barty said. "Obviously it's disappointing tonight that we couldn't execute what we wanted. But still a very positive week."

Now we'll just end it on this: