A blockbuster battle between Serena Williams and Maria Sharapova highlights the Day 9 schedule in Melbourne as quarterfinal action begins. Here’s a preview of what’s on tap.

Tuesday, Day 9
Quarterfinals

[1] Serena Williams (USA #1) vs. [5] Maria Sharapova (RUS # 5)
Head-to-head: Williams leads, 18-2
Key Stat: Williams has won 17 straight decisions against Sharapova, a streak that dates back more than a decade.

There’s no denying that the numbers make a case for a predictable outcome. Serena Williams has—quite remarkably—defeated Maria Sharapova on 17 consecutive occasions and only lost three of her last 37 sets against the Russian, and yet when these two iconic forces meet there is always an air of electricity surrounding the affair. That can be chalked up to several factors. One, starpower; Two, sheer athleticism; Three, competitive fire. Both Sharapova and Williams possess all three of the aforementioned entities in spades, and plenty of Grand Slam hardware to boot. And even though Williams has thoroughly dominated this rivalry over the last 11 years, the one-sidedness has not detracted from the intrigue. “Every match is new,” Williams said of the upcoming quarterfinal with Sharapova. “You know, she always brings in something new and something special.”

Williams remains confident in her game after four breezy wins in Melbourne but she admits that the psychology of having such a long winning streak against a formidable opponent creates a strange dynamic. “I think the person who is winning could definitely feel the pressure because there is a lot of expectations,” she says. Meanwhile, Sharapova enters the matchup with a sense of brimming hope. She’s serving as well as she ever has, as 37 aces in her last two matches can attest, and she’s upped the aggression in her ground game, which could help her avoid having her movement exposed by the quicker Williams. “You’re always trying to improve,” Sharapova said on Sunday after her fourth-round win over Belinda Bencic. “I got myself into the quarterfinal of a Grand Slam. There is no reason I shouldn’t be looking to improve and to getting my game in a better position.” Could these new wrinkles help Sharapova finally get over the hump against Williams? Or will Williams once again prove to be an unsolvable puzzle for the hard-hitting Russian?

Pick: Williams in three

[4] Agnieszka Radwanska (POL #4) vs. [10] Carla Suárez Navarro (ESP # 11)
Head-to-head: Radwanska leads, 3-1 (counting Fed Cup)
Key Stat: Radwanska is currently on a 12-match winning streak that dates back to last year’s WTA Finals in Singapore.

Two of the tour’s most cherished players will duke it out for a coveted semifinal slot at the year’s first major. Radwanska, a semifinalist in 2014 in Melbourne, has won three of four matches against Suárez Navarro, but dropped the pair’s last meeting in Miami last year. Though the Pole comes in as the hottest player on the WTA Tour at the moment, she knows she’ll be in for a tough, physical encounter against the resourceful Suárez Navarro. As for the 27-year-old Spaniard, she’s quite familiar with Radwanska’s tactics and form, and knows she’ll have to be on point in order to reach her first career Grand Slam semifinal. “We had really tough matches in the past,” Suárez Navarro said of matching up with Radwanska after dispatching Daria Gavrilova on Day 7. “I know it will be tough for me. I know that because of her style, you have to run a lot, you have to think every point what to do.”
Radwanska had to snatch victory from the jaws of defeat on Sunday, reeling off five consecutive games in the final set to defeat Germany’s Anna-Lena Friedsam, and the magical finish has her thinking that she could be destined for a career-best run down under. “I’m just very happy that I could win the last point,” she said, adding: “I just hope I can go further and do one step forward, make the final.”

Pick: Radwanska in three