ROME, Italy - Serena Williams faces the week's surprise package, Simona Halep, as she looks to return to the final of the Internazionali BNL d'Italia for the first time since 2002, while Sara Errani flies the home flag in the other semifinal against Victoria Azarenka.
 Serena Williams (USA #1) vs. [Q] Simona Halep (ROU #64)
Head-to-head: Williams leads 1-0
It has been a week of firsts for Simona Halep. On Tuesday she scored her first win over a Top 5 player (Agnieszka Radwanska), on Friday she reached her first Premier Mandatory semifinal and on Saturday she will bid to become the first qualifier to reach the final at the Foro Italico. Standing in between her and that last achievement is a certain Serena Williams.
After some erratic performances en route to the title in Madrid last week, Williams has been playing timeless tennis in the eternal city, dispatching the talented trio of Laura Robson, Dominika Cibulkova and Carla Suárez Navarro for the loss of just seven games.
Halep, on the other hand, has taken more than nine hours to make her journey from qualifying to the last four, including saving two match points in her rollercoaster encounter against former champion Jelena Jankovic. In getting this far, the Romanian has showed brains, bravery and a little brawn and she will need all of that and then some to derail the Williams juggernaut.
 Victoria Azarenka (BLR #3) vs.  Sara Errani (ITA #6)
Head-to-head: Azarenka leads 5-1
On Saturday afternoon, Sara Errani will bid to become the first Italian since Rafaella Reggi 28 years ago to reach the Rome final. If she is to do that, though, she will need to score her first ever Top 5 victory. And the ominous statistics do not end there; Errani's semifinal foe, Victoria Azarenka, has won five of their six career meetings, with the last four all coming in straight sets.
Yet despite all the numbers pointing to an Azarenka win, the intangibles favor the Italian; the raucous crowd at the Foro Italico will be heavily behind their compatriot, who goes into the contest as the more match tight of the two, having played more than three times as many clay court matches as Azarenka in 2013.
Stylistically, the World No.3 is likely to play the part of the aggressor, with the indefatigable Errani settling into her usual role of counterpuncher. Past encounters suggest Errani will need a fast start to help convince herself, Azarenka and the Court Centrale faithful that the upset is possible.