Jankovic wins in breeze

Fourth seed Dinara Safina, number 10 Tatiana Golovin and unseeded Venus Williams also advanced to the last eight at the $1.3 million tournament.

Jankovic lost to Italian Santangelo in three sets in the third round at Miami last month, but her first serve proved dominant in the windy conditions.

"I didn't expect to have such a short match like this because before we had some tough matches and she has a really tough game," the Serb told reporters.

Safina eliminated Spain's Lourdes Dominguez Lino 6-2 6-2 in their first career meeting. The Russian will play Golovin, who overcame China's Shuai Peng 6-2 4-6 6-3.

France's Golovin won her first WTA Tour event last week at Amelia Island, Florida, to climb to 19th in the world rankings.

Williams, a five-times grand slam champion whose world ranking has slipped to 29 due partly to a wrist injury, beat Taiwan's Chan Yung-Jan 6-2 6-1.

"I'm eager to play and I'm eager to get my ranking up," said Williams, who blasted a 125 mph serve against Chan. "I want to play matches, so I'm excited about the snowball effect."

Williams will face Spain's Anabel Medina Garrigues, who upset eighth seed Li Na 6-4 7-5.

Jankovic will play Slovenia's Katarina Srebotnik, a 7-5 7-6 winner over China's Zheng Jie.

Seventh seed Ana Ivanovic of Serbia lost to number nine Vera Zvonereva of Russia. She will meet Michaella Krajicek, who upset 15th seed Sybille Bammer of Austria, 6-7 6-2 6-1.