"I knew the court and I felt like I was hitting the ball well.''
The result, her 24th singles victory in 28 matches, continued a rich vein of form for Erakovic, who began the year ranked 324th after reaching a career-high 49th in the world in 2008 only to suffer hip and leg injuries.
"I went into a slump just before the injury and was beginning to question whether this tennis thing was for me,'' Erakovic told reporters.
"The injury made me realise how much I love tennis and that's when I committed myself. Coming back I feel like I can compete with the best.''
Now free of injury, the 23-year-old reached the second round of the singles and the double semifinals at Wimbledon in June - when Azarenka reached the singles semifinals - after getting plenty of court time on the lower tier ITF circuit where she won three titles in March and April.
She reached the main draw at the French Open, exiting in the first round ahead of Wimbledon at London where she went one round deeper.
Today, she overshadowed a world top 10 opponent with a consummate allround display despite Azarenka's superior first serve percentage.
Erakovic nailed 56 percent of her first serves compared to Azarenka's 67 percent but tellingly the New Zealander won 77 percent of the first service points to her rival's 68 percent.
Erakovic broke Azarenka for the first time in the pivotal 12th game of the second set to secure it 7-5, held serve in the first game of the deciding set, then broke for a second successive game to claim a vital 2-0 lead.
She then held each of her service games and broke Azarenka again, in the final game, to clinch a memorable result.
Erakovic next meets world No 19 and tournament eighth seed Dominika Cibulkova, of Slovakia, for a place in the quarterfinals.
- NZPA
