HOUSTON, US - Lorena Ochoa fired a first-round 66 Thursday to hold a one-shot lead in the LPGA's season-ending Tour Championship.

Ochoa was one shot in front of Reilley Rankin, and nothing at the top was set to change when the four groups who failed to finish because of darkness returned to complete their rounds on Friday morning.

Michelle Wie, fresh from her first professional triumph at the Ochoa-hosted LPGA event in Mexico last week, was hampered by a sprained left ankle as she shot a 72.

Wie, who first hurt her ankle at the Solheim Cup in August, said she was going for treatment after her round and could withdraw.

Ochoa, the world number one who is trying to add to her three straight Player of the Year awards, teed off early before the winds picked up.

She is four shots in front of Jiyai Shin (70), the South Korean who has already wrapped up Rookie of the Year honors and brought an eight-point lead over Ochoa in the Player of the Year race into the tournament.

For Ochoa to earn a fourth consecutive player of the year title, she must win this week or finish no worse than third and hope Shin places out of the top 10.