Wozniacki and Azarenka face off, more Day 4 matches to watch
Caroline Wozniacki and Victoria Azarenka square off
The best match of the day didn't even earn a spot on Rod Laver Arena. The two former No. 1s will face off in the first night match on Margaret Court Arena in a match that serves as a big hurdle for No. 8 Wozniacki and an important litmus test for two-time champion Azarenka. A win for Azarenka would not only set herself up for a deep run in Melbourne, but also serve as a pronouncement that she's playing near her pre-injury level. After spending a significant portion of the 2014 season on the sidelines due to a foot injury, Azarenka is down to No. 44 in the rankings.
Wozniacki leads the head-to-head 4-3 but two of their last three completed matches have gone the distance.
"I know she's very dangerous," Azarenka said. "We always had some of tough matches. I would like to focus on myself and what I can do to build my game, to prepare as best as I can, and just compete. That's my key word for this tournament: Compete."
Serena Williams plays Vera Zvonareva
This was a Wimbledon final five years ago back when Zvonareva finished the season at No. 2. Now down to No. 203 after suffering a shoulder injury, the two face off in the second round.
CoCo Vandeweghe and Madison Keys go for Aussie upsets
It won't be easy but it can be done. Madison Keys plays No. 29 Casey Dellacqua (third match, Margaret Court Arena) and CoCo Vandeweghe goes under the lights on Rod Laver Arena to take on Australia's best, No. 20 Sam Stosur (second night match, Rod Laver Arena.) Vandeweghe beat Stosur in their last match 5-7, 7-5, 7-5 in Miami last year. Keys beat Dellacqua in their only meeting two years ago here in the first round 6-4, 7-6 (0).
Novak Djokovic and Stan Wawrinka look to continue their form
Both men blitzed through their opening rounds and should do the same on Thursday. Djokovic plays No. 88 Andrey Kuznetsov (third match, Rod Laver Arena) and Wawrinka plays No. 194 Marius Copil (second match, Margaret Court Arena).
More matches to watch
Gael Monfils  vs. Jerzy Janowicz (fourth match, Hisense Arena): Two of the most explosive, unpredictable players on one court. Your guess is as good as mine as to what will happen.
Kei Nishikori  vs. Ivan Dodig (first match, Hisense Arena): Nishikori has won their last two matches but Dodig can be a tough opponent.
Steve Johnson vs. Santiago Giraldo  (first match, Court 15): This is a big opportunity for Johnson to make the third round of a major for just the second time in his career.
Venus Williams  vs. Lauren Davis (first match, Margaret Court Arena): A win would put Venus into the third round for the third straight Slam.
John Isner  vs. Andreas Haider-Maurer (first match, Show Court 2): Isner tries to back up his clean win in the first round, where he only had to play one tiebreaker.
Petra Kvitova  vs. Mona Barthel (third match, Hisense Arena): Kvitova had a non-nonsense first round win but we still feel the need to keep an eye on her. Barthel can be tough to beat if she finds her rhythm.