Paula Creamer shot an opening Lotte Championship round of 66 at the Ko Olina Golf Club to lead the field alongside Lee Mi-hyang.
Allen became the first American to finish first on the Ladies European Tour Order of Merit past year.
Canada's Alena Sharp, South Korea's Lee Mi-Hyang and Stacy Lewis of the U.S. are one shot back of the co-leaders at eight-under 136.
There are five golfers at 7 under, including second-ranked So Yeon Ryu (69), coming off a victory in the major ANA Inspiration, and Olympic champion Inbee Park. She'd had success with her standard putting grip in the past and decided it was time to change back. "I adjusted my swing a little bit", said Ariya who finished second twice this year in the HSBC Women's Champions in Singapore and the Bank of Hope Founders Cup in Phoenix. "So, this is an event I really look forward to and I'm excited to go out there and hopefully have a lot of fun this week." said, Wie. "We talked about how many times I won conventional and how many times have I won left-hand-low, and the difference was astronomical".
Lydia Ko carded a one-over 73 in the first round of the Lotte Championship. Hawaii's Michelle Wie, who won here in 2014, is tied for 60th at 1 under.
The two-time LPGA Player of the Year is winless in her last 69 starts. - and 8 under on Ko Olina's front nine this week. The former world No. 2 has played in this event every year since 2012 and is the only American to win here. Usually when a player putts left-hand low, they're trying to keep their right hand from being too dominant. Her midway total score was nine under-par-135.
"I always try not to be negative", she said. Yesterday I hit the ball pretty well, just didn't make any putts.
The trio have been grouped together for the first two rounds and Thursday's play would have been tough viewing for Ko as So shot a four-under 68 to sit in a share of eighth, with Jutanugarn just one shot behind her.