Two Russians, two Americans face-off in AusOpen women's semifinals

MELBOURNE -- Americans! Russians! Oh my! It's a throwback Thursday at the Australian Open as the women's semifinals feature one All-American affair, one All-Russian affair, with a potential No. 1 vs. No. 2 final in the cards. 

No. 2 Maria Sharapova vs. No. 10 Ekaterina Makarova

The first semifinal sees the first all-Russian semifinal at a Slam since 2009. Sharapova has lost just one set to Makarova in five previous matches. Their last match came two years ago in Melbourne in the quarterfinals, which Sharapova won 6-2, 6-2. 

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Sharapova goes into the match on a 9-0 streak to start the 2015 season after winning the Brisbane International in mid-January. She has lost just one set coming into the match -- she saved match points to defeat No. 150 Alexandra Panova in the second round -- and is coming off her best performance of the tournament. In the highly-anticipated semifinal against Eugenie Bouchard, Sharapova was lights out, defeating the young Canadian 6-3, 6-2. A win would keep Sharapova's slim chance at the No. 1 ranking alive. She needs to win the title and hope Serena Williams does not advance past the semifinals.

Sharapova clearly has the experience, but Makarova is into her second consecutive Slam semifinal after earning her career-best result last fall at the U.S. Open. The 26-year-old has not lost a set through five matches and ousted No. 3 Simona Halep 6-4, 6-0 in the quarterfinals. 

This match is all about Sharapova. Since the start of the 2011 season, she is 21-1 against her fellow Russians. Her five wins over Makarova are the most against any other compatriot. She's also 50-11 against left-handers.

No. 1 Serena Williams vs. No. 35 Madison Keys

While Sharapova and Makarova got an extra day of rest, Serena and Keys have just 24 hours to rebound for their semifinal clash. That's particularly bad news for Keys. The Slam semifinal debutante aggravated a left adductor injury in her three-set win over Venus Williams on Wednesday, and the injury clearly hampered her movement out wide and her powerful serve. She'll need to be 100 percent to challenge Serena.

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This will be the first meeting between the two and the first All-American semifinal since the 2002 U.S. Open between Serena and Lindsay Davenport. Davenport is now in Keys' box, having taking up coaching duties with the 19-year-old with immediate success. Keys is trying to become the first player to beat both Venus and Serena in a major since Kim Clijsters at the 2009 U.S. Open. 

Should she win, Serena will not only clinch the No. 1 ranking for the tournament but also become the oldest woman to reach the Australian Open final in the Open Era. After a slow start to the tournament, Serena has rounded into top form. Her 6-2, 6-2 win over Dominika Cibulkova on Wednesday was the best she's played in January and her destructive serve has finally shown up in Melbourne. With Keys struggling with an injury and Serena back to playing her best, it's hard to bet against the more accomplished American to move through.