South Korean Inbee Park and Taiwan's Yani Tseng both shot 6-under 66 on Thursday to share the lead after the opening round of the HSBC Women's Champions.
Park's sixth birdie on the par-5 18th at Sentosa Golf Club left her tied with Tseng, who carded seven birdies against a lone bogey.
Angela Stanford of the United States was in third place one stroke back.
Top-ranked Lydia Ko offset two bogeys with six birdies for a 68 and was tied for fourth with Karrie Webb, Jenny Shin, Mo Martin and Mariajo Uribe.
The 17-year-old Ko won her previous two tournaments.
Paula Creamer, who won last year's tournament with a 75-foot putt, struggled to a 74. Michelle Wie had a 73 that included a double bogey on the par-5 No. 7.