Second-seeded Danielle Collins lost in the second round of the Guadalajara Open on Wednesday and third seed Victoria Azarenka withdrew from her match because of injury. Qualifier Olivia Gadecki, ranked No. 152, pulled off a major upset with a 6-3, 6-3 win over Collins to reach the quarterfinals of an elite WTA tournament for the first time. The 30-year-old Collins, who is retiring at the end of the season, arrived at Guadalajara with 39 tour-level wins and two titles on tour this year and is currently ranked 11th.