Wozniacki reached the semi-finals with a 6-3, 6-4 win over Russian Nadia Petrova while Daniela Hantuchova rallied to beat Jankovic 1-6, 6-3, 6-3.
Wozniacki will face seventh-seeded Russian Vera Zvonareva, a 7-5, 6-2 winner over American Melanie Oudin.
"I feel like I'm playing very well," said the second-ranked Wozniacki, who won last week at Ponte Verde Beach, Florida. "I'm very confident, and I've got some good results with my play."
Jankovic won the first three games of the opening set en route to a 6-1 win. But then she fell apart losing the first four games of the second set.
"I played really well in the first set and I played really aggressive," said Jankovic. "But then I just stopped and I especially had trouble hitting my backhand."
It marks the first time in three years that Hantuchova has beaten a top ten ranked player.
"Definitely, I felt very good on the court today, even though the first set was not easy," Hantuchova said.
Slovakian Hantuchova said her strategy changed in the second set.
"I tried to put a little more on the ball, move her a little more around and stay more aggressive, and that made the difference," she said.
Hantuchova next faces Aussie Samantha Stosur who beat Peng Shuai of China 6-4, 6-1.
Stosur trailed 3-4 in the first set against the unseeded Peng.
"I got that break down, and on that change of ends I thought I had to step it up a gear and not play so many straight shots through the middle and give her a chance to hit it," Stosur said.