Aleksandra Wozniak suffered a shoulder injury while warming up for her match against Melanie Oudin and was forced to retire on Thursday at the Bell Challenge tennis event.
Top-seeded Spaniard David Ferrer and countryman Nicolas Almagro were easy second-round winners Wednesday at the $1.227 million Mexican Open tennis event.
In a battle of former champions, Mardy Fish swatted Ricardo Mello in Thursday's second-round action at the $442,500 Delray Beach International Tennis Championships.
Jelena Jankovic had little trouble moving past Spaniard Lourdes Dominguez Lino in their opening round match Wednesday at the $220,000 Monterrey Open tennis event.
Four-time Miami runner-up Maria Sharapova rolled to a straight-set victory in Friday's second round, while two-time champion Victoria Azarenka aggravated a right ankle injury and was forced to pull out of the Sony Open tennis event.
Talented Latvian Ernests Gulbis and former world No. 3 Nikolay Davydenko were among the Day-1 winners at the $2.23 million Barcelona Open tennis event.
Third-seeded Alize Cornet reached the quarterfinals, while former French Open champion Francesca Schiavone posted a first-round victory Wednesday at the $235,000 Moroccan Grand Prix.
Third seed Agnieszka Radwanska, fourth- seeded Chinese star Li Na and last week's Tokyo titlist Petra Kvitova were among the winners Wednesday at the $5 million China Open.
Sixth seed Fabio Fognini and French crowd favorite Gael Monfils were among Tuesday's first-round winners at the $530,000 Nice Open, a final clay-court French Open tune-up.