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LIVE: Nishikori takes two set lead over Karlovic

Japanese superstar and eighth seed Kei Nishikori faces Croatian veteran Ivo Karlovic for a place in the Australian Open third round. Follow all of the action right here.

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Australian Open Day 4 preview

Stephanie Brantz and Chrissie Evert preview the matches to watch on Day 4 at the Australian Open.

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Day 4 Australian Open preview: Serena Williams, Novak Djokovic face difficult foes

They didn't need to work very hard in the opening round at the Australian Open, but on Day 4, Serena Williams and Novak Djokovic face tough opponents.

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Australian Open - Day 4

Men's scores

Australian Open - Day 4

Women's scores

Americans at the Aussie

Amanda Anisimova, Frances Tiafoe and career-defining matches for the Americans

The next generation of American players put on memorable shows Wednesday at the Australian Open. Here's a look.

Stephens tops Babos in straight sets

Sloane Stephens is able to overcome Timea Babos in straight sets, 6-3, 6-1, to move onto the third round of the Australian Open.

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Nadal to face Aussie de Minaur

Nadal enjoying improved serve, renewed passion

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'Demon' brings back pride to Aussie men's tennis

Whether he won or lost, Alex de Minaur's epic performance against Henri Laaksonen was a vintage reminder of the characteristics many Aussie tennis fans cherish.

WTA action

Who's going to catch Simona Halep as the world No. 1? The race is on

So many players are chasing Simona Halep as the world's top player. But which contender comes out on top is anyone's guess.

Sharapova advances to set up showdown with Wozniacki

Maria Sharapova beats Rebecca Peterson 6-2, 6-1 to move on to the third round of the Australian Open.

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Wozniacki cruises into the 3rd round

The reigning champion, Caroline Wozniacki defeats Johanna Larson in straight sets (6-1, 6-3) to advance to the third round of the Australian Open.

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Home hero Barty powers on

Barty time! Why Ash should be the main attraction in Melbourne

Forget Bernard Tomic. Forget Lleyton Hewitt. Ash Barty deserves the attention and spotlight at this year's Australian Open, writes Jake Michaels.

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Barty pleased with elevated aggression

Australia's Ash Barty is happy with her form after progressing to the third round of the Australian Open.

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Serena Williams

Was Serena singled out in the US Open final? Here's what 73 matches told us

There is still much debate over whether Serena Williams was wrongfully penalized by chair umpire Carlos Ramos in the US Open women's final. Since then, we've watched dozens of matches to find out if the numbers land on either side of the argument.

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Serena's statement is clear: She's focused on the future

With the US Open controversy in the rearview, Serena Williams made it clear that this year's Australian Open represents a fresh start for her.

Serena wins 1st round match in straight sets

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