Scotland's Catriona Matthew carded an opening round of 64 to top the leaderboard at the Airbus LPGA Classic in Alabama.
Matthew is a stroke clear of England's Charley Hull, who shot a 65.
Ji Eun-Hee, Suzann Pettersen and 2012 winner Stacy Lewis were all tied for third following their opening rounds.
Matthew, who started on the back nine, eagled the par-five 13th and a run of four consecutive birdies propelled her to the top of the leaderboard.
Hull, among the later starters, set a steady pace, making the turn in 32 and hovering around the lower end of the top 10 before back-to-back birdies on the 17th and 18th catapulted her into second place.