INDIAN WELLS, CA, USA - Friday's evening session at the BNP Paribas Open will see all four semifinalists in action. First up are Victoria Azarenka and Angelique Kerber, before being followed on court by the battle of the former champions between Maria Sharapova and Ana Ivanovic.
 Victoria Azarenka (BLR #1) vs.  Angelique Kerber (GER #19)
Head-to-head: first meeting
Last Friday, both Victoria Azarenka and Angelique Kerber looked on the verge of suffering shock second round exits. Seven days later, they face one another for a place in the final. And while the turnaround is dramatic, it is not surprising; both players have enjoyed outstanding starts to 2012, winning four titles and a staggering 39 matches between them.
Twenty-one of these wins have come from Azarenka, who now stands just one away from recording the best start to the season since 1997. The top seed has improved with each passing match in Indian Wells, culminating in a quarterfinal demolition of Agnieszka Radwanska. Next into the firing line is Kerber, who at 24 is finally starting to produce the consistency - she has reached the semifinals or better at seven of her last 11 events - to match her talent. Against Li Na on Wednesday, Kerber showed that she has both the shots, and the temperament, to live with the best, and more of the same is required if she is to become the first German since Steffi Graf in 1999 to reach the final here.
 Ana Ivanovic (SRB #16) vs.  Maria Sharapova (RUS #2)
Head-to-head: Sharapova leads 3-2
Over the last week Ana Ivanovic has confirmed the old adage that form is temporary and class permanent. Back-to-back wins over two members of the Top 10, Caroline Wozniacki and Marion Bartoli, brought back memories of the Serb's annus mirabilis of 2008, when, in addition to a title run in Indian Wells, she won the French Open and held the No.1 ranking. And victory over 2006 champion Maria Sharapova would well and truly put her back in the big time, with her first final appearance at a WTA Premier event since she finished runner-up here back in 2009.
However, defeating Maria Sharapova is easier said than done. Like Ivanovic, she has dropped just one set en route to the last four, and presents a daunting challenge on her favored hardcourts. The two have met five times, with the last of these coming back at the start of 2008, when Sharapova triumphed in the final of the Australian Open. Ivanovic will be keen to exact revenge for this result, and if her forehand fires as it has in the last few rounds then she is more than capable of succeeding.
For more on today's matches, see our Match Notes in the Press Center.