Ochoa had no bogeys to finish 6-under 66 at Asias richest womens golf event at Tanah Merah Country Club.
It was one of those days that I was getting the ball and making good contact especially, had a lot of birdie chances, Ochoa said. It was a great start.
Ochoa was confident of her form after taking a break in December and starting practice in January.
I am 100 percent ready to go, she said. Its why I took a few more weeks to practice and why I am here.
American Paula Creamer and Japans Ai Miyazato both had six birdies and a bogey to share second place, a stroke behind Ochoa.
Creamer, who won the Fields Open last weekend, compensated for some missed putts with impressive birdies from 15 and 20 feet.
I missed a lot of putts but the ones that I holed were fairly big breakers, she said. Theres not many straight putts that you have out there.
Miyazato also noted that the par-72, 7062-yard Garden course was challenging.
Its pretty tough, Miyazato said. The fairways are narrow and the greens are sloppy, but the good thing is I can concentrate on hitting my shots. The shots felt really nice.
The tournaments field of 78 players features 18 of the top 20 players in the world vying for a top prize of $300,000.
Linda Wessberg of Sweden was two strokes off the lead at 4-under 68, along with South Koreans Kim In-kyung and Lee Jee-young.
Former No. 1 Annika Sorenstam had three birdies and two bogeys to finish 1-under 71 and shared 19th place.
Sorenstam won her 70th LPGA Tour title at the SBS Open this month in Hawaii, ending a 17-month title drought and vaulting her two spots to No. 2 in the world.
Suzann Pettersen of Norway, who had a breakout season last year with five wins including the LPGA Championship, had one birdie and a bogey to finish even par, six strokes off the lead.
Australias Karrie Webb had a 3-under 69 and shared seventh place.