Victoria Azarenka (left) and Sloane Stephens haven't met since last year's Australian Open. (Quinn Rooney/Getty Images)
MELBOURNE, Australia -- Two blockbuster rematches from last year's Australian Open headline the schedule Monday as the fourth round concludes. Here are the matches to watch on Day 8. Tennis Channel will have two hours of coverage starting at 7 p.m. ET, and ESPN2 will take over at 9 p.m.
Victoria Azarenka  vs. Sloane Stephens  (second match, Rod Laver Arena): Stephens once said of Azarenka, "You could tell me she sucks toes -- I wouldn’t care. She’s been nice to me since I met her for the first time. She and my mom are always chatting it up. People are always telling me they hate her. I don’t know why.”
Those comments came before their controversy-tinged semifinal last year, which Azarenka won 6-1, 6-4. That match isn't remembered for the fact that Azarenka mostly outclassed her younger opponent en route to the title. What people remember is Azarenka's taking a medical timeout near the end of the second set that stalled the momentum of Stephens, whose then-coach, David Nainkin, called the move "cheating within the rules."
When asked about her relationship with Azarenka now, Stephens kept it simple: "It's nonexistent," she said after her third-round win.
Both women say they've put that match behind them and that it has no bearing on Monday's encounter. Psychological intrigue aside, this should be a very good match. Stephens, 20, the last American in the draw, is the rare player who can play both effective defensive tennis and powerful, assertive tennis. I expect Stephens to come out aggressively and try to get the two-time defending champion on the run.
Roger Federer  vs. Jo-Wilfried Tsonga  (first night match, Rod Laver Arena): Federer won a five-set quarterfinal here last year against Tsonga, who got revenge on home soil when he beat the 17-time major champion in straight sets at the French Open. Neither man has dropped a set through three rounds, but this is a huge step up in competition level, particularly for Federer, who hasn't played anyone ranked higher than 79th.
Two of Tsonga's four wins over Federer in 13 meetings have come on hard courts, but they were best-of-three matches that went the distance. I like Federer's chances on this surface and in this best-of-five format. However, this will be a huge test for his confidence, especially if Tsonga takes the first set.
Maria Sharapova  vs. Dominika Cibulkova  (first match, Rod Laver Arena): Sharapova has scratched and clawed her way into the fourth round despite an unconvincing level of play. After beating Alize Cornet 6-1, 7-6 (6) in the third round, she went right back out to the practice courts. Cibulkova, meanwhile, has lost just two games in her last two matches, including a 6-1, 6-0 victory over No. 16 Carla Suarez-Navarro. Her big-hitting, go-for-broke game has bothered Sharapova in the past. The Russian leads the head-to-head 3-2, but the two have never played on a hard court. An upset here would not surprise me.
Jelena Jankovic  vs. Simona Halep  (second match, Hisense Arena): This is where the rubber meets the road for two of the hottest women at the end of last season. Jankovic has won three consecutive straight-set matches against Japanese players ranked outside the top 60. Halep, who broke out in 2013 with a six-title season, survived the heat to beat Varvara Lepchenko in three sets in the second round but has otherwise had a straightforward run to her best result in Melbourne. She leads the head-to-head 2-1 and has won their last two matches.
Garbine Muguruza vs. Agnieszka Radwanska  (second night match, Rod Laver Arena): Muguruza has won 11 matches in a row and is coming off a breakthrough win over No. 10 Caroline Wozniacki in the third round. You have to think her mojo runs out at some point, but she's precisely the type of big-hitting opponent who can trouble the crafty Radwanska. Muguruza plays a lot like Radwanska's third-round opponent, Anastasia Pavlyuchenkova, who took the first set off the Pole before taking a medical timeout and struggling the rest of the way.