Ochoa fired four birdies and one bogey in Friday's second round for a 69 that put her at 136, 8-under-par, after 36 holes.
Ochoa started the round three shots behind first round leader Becky Morgan of Wales, who carded a 2-over-par, 74 to follow up her 64 on Thursday. Morgan is now in second place, tied with Sweden's Maria Hjorth at 138.
A rookie on the women's tour, American 18-year-old Paula Creamer, is another shot back at 139.
World number one Annika Sorenstam of Sweden is not competing in the Rochester tournament. She won her third straight McDonald's Championship last week, the 62nd victory of her career.
Some information for this report provided by AFP and AP.