Grimes is the only past SALLY champion in the field and is tied with Taylor Leon for second place, just one stroke behind Julieta Granada of Paraguay.
Both Grimes and Leon scored 73s on a blustery day. The 20-plus mph winds, forced players to make two or three club adjustments to compensate. A brief but heavy burst of rain also made play a bit tougher than Wednesday.
Granada carded a 74 for a 1-over 145 total to maintain her lead.