Lydia Ko has made a strong start at the Lorena Ochoa Invitational tournament in Mexico City.
The world number three and LPGA rookie of the year fired a four-under 68 to sit in third place. American Christina Kim holds the first-round lead at seven-under, a shot ahead of Spain's AzaharaMunoz.
The New Zealand teenager was three-under at the turn before dropping a shot at the par five 11th. However back-to-back birdies on the final two holes saw Ko secure sole third place at the end of day one.
Ko was grouped with world number one Inbee Park and number two ranked player Stacy Lewis.
Park needed two late birdies to finish with a two-under 70 and sit in seventh, while Lewis struggled with a four-over 76 to lie 31st in the 36-player field.
Ko needs to finish ahead of world number four Michelle Wie to ensure a chance to win the $1 million jackpot at next week's season-ending CME Group Tour Championship.
Wie opened with a one-over 73.
Danny Lee fired a five-under 66 to sit just one shot off the lead at the OHL Classic at Mayakoba in Mexico. Six players share the first-round lead.
Fellow New Zealander Tim Wilkinson is two shots back in a tie for 29th after a three-under 68 while Steven Alker is off the pace after a three-over 74 left him in a share of 118th.