Petra Kvitova of the Czech Republic started with a flurry, winning the first set 6-1.
Victoria Azarenka fought back, levelling the match with a 6-3 win the second set.
But the day belonged to Kvitova, sealing her place in the Wimbledon finals by wrapping up the third set convincingly.
Kvitova became the first left hander to reach the Wimbledon final since Martina Navratilova in 1994.