The 21-year-old Krunic, who aims to graduate from university in Serbia this year with a degree in economics, registered the shock result when the error-prone Czech whipped a cross court forehand just wide of the line.
Kvitova, who made 34 unforced errors in the 98-minute match against the quick-moving Serb, became the fifth seed from the top eight to be dismissed joining Simona Halep (2), Agnieszka Radwanska (4), Angelique Kerber (6) and Ana Ivanovic (8).
Krunic will next play either two-times Australian Open winner Victoria Azarenka of Belarus, the 16th seed, or Russian Elena Vesnina.-Reuters
