World number two Maria Sharapova was forced to withdraw from the Acapulco International just hours before her semi-final against Caroline Garcia.
The Russian top seed was ruled out with a stomach virus and told her official website: "I had a great start to the event and was hoping I could recover but there was not enough time."
Switzerland's Timea Bacsinszky went on to beat Garcia 6-3 6-0 in the final.
David Ferrer beat Kei Nishikori 6-3 7-5 to win the men's title.
Meanwhile, in Doha, Lucie Safarova recorded her first victory over Victoria Azarenka to win the Qatar Open.
The 28-year-old Czech, who had taken only one set off Azarenka in six previous matches, won 6-4 6-3 and will climb four places to 11th in the world rankings.
Safarova made the decisive break in the ninth game of the first set before serving it out.
She sent down three aces to win the eighth game of the second set and then broke her Belarusian opponent to win the title.
"My game improved a lot throughout the last couple of years," said Safarova. "It took me quite a few years to get to this point. I hope it's not a finish point and I can still improve."