Serena Williams sets up Brisbane semi-final with Maria Sharapova
The American produces perfect first serves in the first set of her match

Serena Williams on Thursday served a perfect first set on her way to setting up a blockbuster semi-final against Maria Sharapova at the Brisbane International.
The top-seeded Williams didn't lose a point on serve in the opening set during her 6-3, 6-3 win over Slovakia's Dominika Cibulkova.
In stark contrast to Williams, Sharapova was forced to recover from an error-strewn start before eventually downing 2012 champion Kaia Kanepi in three sets, 4-6, 6-3, 6-2.
Today's semi-final will be the 17th meeting between the two superstars of the women's game, who make no secret of their frosty personal relationship.
Williams holds a clear advantage over the Russian, winning 14 times against Sharapova, including the last 13 in a row.
Their most recent clash was in the final of last year's French Open, where Williams won a tight battle 6-4, 6-4.
"Some of the matches were a bit closer than others," Sharapova said of her run of 13 losses.