It was the second title of the year for the sixth-seeded Dane after she won in Ponte Vedra Beach, and the fifth of her career.
After upsetting top-seeded Elena Dementieva and defending champion Agnieszka Radwanska, Razzano was seeking her third career title and her first win over Wozniacki in three meetings.
Wozniacki broke to lead 4-2 when Razzano netted a smash after just one point was dropped on serve in the first five games.
But she failed to serve out the set at 5-3 as Razzano struck a forehand winner to recover the break, before claiming the tie-breaker 7-5 on her fifth set point.
In the second set, Wozniacki broke to lead 1-0, but Razzano levelled at 4-4 after three consecutive breaks from 3-2.
Wozniacki then survived a set point at 5-4 when Razzano netted a backhand, and another backhand error from Razzano gave Wozniacki a decisive break for 6-5.In a final moment of drama, Wozniacki yelled in triumph after she thought she had struck an ace on her first match point, only for her serve to be called wide. But she closed out the match four points later when a Razzano drop shot fell short.
Meanwhile, Russian second seed Dmitry Tursunov denied Canadian qualifier Frank Dancevic a first tour title on Saturday when he won the men's crown at Eastbourne 6-3, 7-6 (7-5).
The 26-year-old California-based Tursunov, ranked 27 in the world, carried off his first grasscourt title with his third success in as many meetings with Dancevic to earn his sixth career title.
Tursunov, who needed treatment for an ankle knock in the closing stages, said he was seeking a good showing at Wimbledon after reaching the last 16 in 2005 and 2006.
