WTA Insider Courtney Nguyen | A win over Williams continued to elude Sharapova, while sleep eluded Carla Suárez Navarro, contributing to her own loss. This and more Day 9 quotes.
WTA Staff

MELBOURNE, Australia - On Day 9 at the Australian Open, Serena Williams and Agnieszka Radwanska won through to set up a semifinal clash, their first match since 2013.

Serena has her game face on: Make that 18 consecutive wins over Maria Sharapova. Serena continued her solid form through the tournament with a 6-4, 6-1 win over the No.5 seed to advance to the semifinals. The first set remained tight after Serena overcame a slow start - she's been struggling with food poisoning - and Sharapova lost a game point serving at 4-5 in the first set on a tough-luck netcord. But Sharapova just couldn't capitalize on her small window of opportunities and Serena ran away with it in the end.

Full match recap here.

Agnieszka Radwanska continues her Slam streak: With a 6-1, 6-3 win over Carla Suárez Navarro, Radwanska advanced to the semifinals or better at a Slam for the fifth consecutive year. Radwanska goes into the semifinal against Serena having lost just one set all season and riding a win-streak of 12 matches, dating back to her run to the title at the BNP Paribas WTA Finals Singapore presented by SC Global.

"Well, in hindsight, yes, especially that you playing there only against top players, and that give me always more confidence," Radwanska said, when asked whether the WTA Finals boosted her confidence.

"But I was saying before, this is new season, new Grand Slam; you're starting over again. So it's not like you winning Champs so you have easier draw or easy way to the semis."

Serena's perfect record: Serena has made the Australian Open semifinals six previous times. She has gone on to win the title every time. An omen?

Back to the drawing board for Sharapova: Sharapova served a career-high 21 aces in the fourth round against Belinda Bencic but tallied just 3 aces, compounded with 7 double-faults on Tuesday. Without getting any free points on her serve, Sharapova's margin of error grew smaller. It's a tough problem to solve.

Maria Sharapova

"I think if you're serving maybe 180kph against somebody else compared to Serena, that's an ace. Against Serena, as we all know, the return is one of her great strengths. She's very explosive. She stays quite close to the baseline. She cuts the ball early. She doesn't give you many angles. That's the reason I can't get so many free points against her."

"Serena's on a different level.": Sharapova: "It's motivating because she's at a different level. She makes you go back to the drawing board, not just for me, but for many other players. She makes you work. That's inspiring."

Sluggish Suárez Navarro can't lock in: The Spaniard said she had trouble sleeping the last two nights and the fatigue showed on Tuesday. Her game lacked conviction and she looked a step slow on the court. She did not confirm whether the knee injury she sustained against against Daria Gavrilova had an effect.

"I didn't rest good," Suárez Navarro said. "I feel tired. But when you are on court you have to fight, you have to run, you have to be there, and today I don't have the good feeling to play good tennis, the good mentality to play more aggressive or try to play a little bit better than I play.

"But I have to learn about these situations, this match, this experience. I need to learn."

Despite the disappointment, this was a good tournament for Suárez Navarro, who lost in the first round of three of the four Slams last year (she made the third round at the French Open).

Martina Hingis, Sania Mirza

Doubles semifinals are set: No.1s Martina Hingis and Sania Mirza will play No.13 seed Julia Goerges and Karolina Pliskova, and No.7 seed Andrea Hlavackova and Lucie Hradecka play No.15 seeds Xu Yi-Fan and Zheng Saisai.

Sharapova plans for a light February: Nothing is set in stone, but Sharapova said she plans on dedicating the month to getting her forearm healthy. She'll travel to Moscow for Fed Cup but does not intend to play, and then, "I don't see myself playing anything before Indian Wells."

No, Serena hasn't thought about the "R" word: Odd timing to ask the World No.1 this question mid-tournament after she just made the semifinals without losing a set, but Serena handled it well:

Q. Is there a chance we're seeing you in Australia for the last time?
SERENA WILLIAMS: I don't think so. Hopefully not. Unless you know something I don't know.

Q. It's a big year ahead. You have the Olympics. You've won four gold medals, going for your fifth. Has it entered your mind yet?
SERENA WILLIAMS: It's entered yours, but not mine.

WTA Ranking Watch

By reaching the semifinals, Agnieszka Radwanska will move to No.3 in the rankings and can equal her career-high ranking of No.2 if she defeats Serena Williams and advances to the final in Melbourne. Williams owns an 8-0 advantage in their first eight meetings, dropping only one set.

As a result of Radwanska's jump, Garbiñe Muguruza will dip to No.4 in the rankings and could fall to No.5 if Angelique Kerber advances to the Australian Open final.

Victoria Azarenka has a chance to return to the Top 10 for the first time since August 2014, but will need to reach the final in order to do so. Azarenka is projected to move to No.14 by reaching the quarterfinals, No.11 with a semifinal finish, No. 6 by reaching the final and can climb as high as No.5 if she wins the title; the last time Azarenka was ranked in the Top 5 was at the 2014 French Open.

By advancing to the quarterfinals, Johanna Konta is projected to jump to a career-high No.32 in the rankings after the Australian Open; her previous high was No.46 (reached October 19, 2015). If she wins her quarterfinal match against Zhang Shuai, Konta will move into the Top 30 (No.28), the first British woman to be ranked in the Top 30 since Laura Robson in July 2013, who climbed to No.27.

As a result of Zhang Shuai's storybook run to the quarterfinals in Melbourne, she will overtake Zheng Saisai as the new Chinese No.1 on Monday. Zhang is projected to rise to No.64 and could move into the Top 40 should she reach the semifinals.

All photos courtesy of Getty Images.