Injury problems may have left Azarenka struggling at number 48 in the rankings but she continues to find her best form at the competition she won in 2012 and 2013 before she was unable to compete last year.
She was too good for Wozniacki, sealing a 6-3 6-1 victory and breaking serve six times.
Venus Williams awaits in the last four, boasting a 4-0 winning record over Azarenka in their previous meetings.
Williams needed two hours and sixteen minutes to see off fourth seed Agnieszka Radwanska 6-4 1-6 6-3 in a keenly-fought contest.
Top seed Petra Kvitova was also toppled in the last eight, Spaniard Carla Navarro coming from a set down to grab a 3-6 6-0 6-3 win.
Navarro’s next challenge is Czech Lucie Safarova, who defeated Andrea Petkovic 6-2 6-1.