Paula Creamer shot a 5-under 67 to share the lead with rookie Paige Mackenzie and veteran Sherri Steinhauer heading into Friday's second round.
"They're great players," Steinhauer said about the non-Americans. "We obviously have to step up our game to keep up with them."
There were only three Americans who finished in the top 10 on the 2006 money list. Cristie Kerr was the highest at No. 5.
"Don't ever count anyone out," Steinhauer said. "They are fighters, and at the end of the week that's what counts."
Steinhauer, who won the Women's British Open last year for her second career major, is seeking her seventh LPGA Tour title. The 44-year-old from Wisconsin holed a wedge shot from 105 yards for eagle on the par-4 14th and made a 20-foot birdie putt on the 18th to reach 5 under.
"I'm very, very happy with the start," she said.
The 20-year-old Creamer is seeking her first win since 2005 when she won twice, finished second on the money list and earned rookie of the year honors. Last year, she had 14 top 10 finishes, including a second-place tie in the Tournament of Champions.
"I worked really hard this offseason. I want to win," she said.
Creamer, who earned $1,076,163 last season to set an LPGA record for the most earnings in a season without a victory, was steady all day with a bogey-free round.
The surf was up but the wind stayed down, leaving several players jostling for position on the Palmer Course. Waves as high as 15 feet pounded Oahu's stunning North Shore.
Julieta Granada, the winner of the season-ending ADT Championship, was a stroke back at 68 along with Natalie Gulbis, Sung Ah Yim and Wendy Ward. The group at 69 included Morgan Pressel, Juli Inkster, Yu Ping Lin, Janice Moodie, Irene Cho, Alena Sharp, Hee-Won Han and Stacy Prammanasudh.
In addition to winning the season-ender, the 20-year-old Granada teamed with Celeste Troche to give Paraguay its first Women's World Cup title last month in South Africa. The $1 million paycheck from ADT was the biggest in tour history and pushed Granada's rookie season total to a record $1.6 million, breaking Creamer's 2005 mark of $1.5 million.
In her first start as an LPGA Tour member, Mackenzie opened on No. 10 and made the turn at even par before birdies on five of her last nine holes.
The former University of Washington star earned her tour card by tying for 12th at Q school.
"I don't feel weird if I want to go in the players lounge and hang out because I'm a player now," she said. "I feel more a part of the tour instead of just a visitor. That part is great."
Last year, she tied for 23rd in the Wendy's Championship, helped the U.S. team win the Curtis Cup and became the first player in Washington history to win the Pac-10 Championship individual title.
Karrie Webb was at 70 and 2006 LPGA player of the year Lorena Ochoa was another stroke back.
Big Island native Kimberly Kim, who last year became the youngest champion of the U.S. Women's Amateur at age 14, opened with a 73. A fellow amateur, 16-year-old Taylore Karle, was at 76.
Defending champion Joo Mi Kim struggled to a 5-over 77.