The upset victory in one hour, 42 minutes also denied Azarenka a career-best fourth ranking and prevented the Belarus player from winning her third title of the spring campaign after winning Miami and Marbella back to back.

Azarenka, ranked fifth, has been one of the form players of recent months, and still stands a respectable 19-3 on the season.

Kvitova's resounding victory further cemented her reputation as a giant killer, with Azarenka her ninth career Top ten victim.

The Kvitova list of wins also includes success over Venus Williams (2008 Memphis), Dinara Safins (2009 US Open), Caroline Wozniacki (2010 Wimbledon), Samantha Stosur (2011 Australian Open) and Kim Clijsters (2011 Paris Indoors).

The Czech becomes the second outsider in a row to win the women's event at the Caja Magica after France's Aravane Rezai upset Williams in the 2010 final.

Kvitova, 21, who began the week ranked 18th, took a firm grip in a match littered with seven breaks of serve.

Azaranka was also playing after a late-night doubles finish in the midnight hours in chilly temperatures with all four players bundled up on court. The contrast between that scene and the sunshine of Sunday could not have been more apparent.

Kvitova began the match with a break of serve and held her nerve despite losing the lead when Azarenka broke back in the third game. As the set wound into a tiebreaker, it was the Czech who prevailed, winning the last five points to seal it after 52 minutes.

A run of four breaks in the second set finally ended as Kvitova saved two break points to hold for 5-3. A game later, The desperate Azarenka saved a match point, but Kvitova served out the victory a game later on her second winning opportunity.