Day 7 at the 2012 Australian Open was full of excitement, as we were treated to an inspiring comeback win by Kim Clijsters, another flawless victory by Victoria Azarenka and a dominant performance by top seed Caroline Wozniacki.

Here's what we learned from the thrilling fourth round action on Day 7 of the Aussie Open.

Never Count Out Kim Clijsters

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The defending Australian Open champ refused to go down in the fourth round, saving four match points to fend off No. 5 Li Na.

Clijsters, the 11th seed, was relentless, eventually prevailing 4-6, 7-6 (6), 6-4. She twisted her ankle in the seventh game of the match, but it wasn't enough to stop her from advancing.

In the quarterfinals, she'll have an even tougher test as she takes on the top-seeded Wozniacki. Clijsters will be the underdog, but she's more than capable of winning.

Caroline Wozniacki is Really, Really Good

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We obviously knew that Wozniacki is good, but she reinforced that with a dominant win over No. 13 Jelena Jankovic.

Wozniacki won 6-0, 7-5 in another match where she was never really threatened. She was in control from start to finish, looking every bit like the top overall seed that she is.

Clijsters certainly presents a challenge, but I expect Wozniacki to move one step closer to her first career Grand Slam title.

Victoria Azarenka Still Hasn't Been Tested

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Azarenka, who is also seeking her first Grand Slam title, has been mowing down her opponents so far. However, she has yet to face a single ranked opponent.

On Day 7, the third-seeded Azarenka cruised to a 6-2, 6-2 victory over Iveta Benesova. It was her fourth-straight easy victory, as she has yet to drop a set in the tournament.

We'll find out how good Azarenka really is when she takes on No. 8 Agnieszka Radwanska. If she gets another win, she'll advance to her second Grand Slam semifinal appearance.

With the No.1 seed in the world on the line, I'm expecting Azarenka to dominate again.