"It was a great feeling. I missed some putts early on but coming down the stretch, my putter got really good and I made the putts that I needed to make," said Baena after disposing of Rosales, who went 2-up on the 12th after a birdie-blast.
But Rosales, a Smart endorser, who beat Angela Stanford and Beth Daniel to reach the last 16, failed to sustain her charge as Baena birdied Nos. 14 and 17 to draw level.
Baena then made a long putt on No. 10, the 19th hole, to tie then claimed the victory with a birdie on the 11th.
The Colombian bet kept the momentum of that big victory over Rosales as she beat six-time major champion Karrie Webb of Australia, 2 and 1, in the afternoon match to reach the semifinal round of the $2 million event.
Also tumbling out of the event was Annika Sorenstam, who like Rosales, squandered a two-hole lead with four to play in her quarterfinal against 23-year-old Candie Kung.
The eighth-seeded Kung will face 60th-seeded Marisa Baena of Colombia in the semifinals on Sunday. Baena beat six-time major champion Karrie Webb of Australia 2 and 1.
In the other semifinal, 14th-seeded Wendy Ward will play No. 47 Meena Lee of South Korea. Ward beat 59th-seeded Sophie Gustafson, 2 and 1, and Lee held off No. 39 Pat Hurst, 1-up.
After conceding a 2-foot par putt to Kung on the par-4 18th, Sorenstam slid her 8-foot par try well right of the hole to end the match.
"I had a great chance — 2-up with four to go," Sorenstam said. "Candie played very well. Sometimes it just doesn’t go your way. To finish with a bogey doesn’t make you very happy."
Both players missed the green with their approach shots, with Kung’s ball finishing hole-high to the left. (AP)