Stacy Lewis has streaked into the lead at the Navistar LPGA Classic with a seven-under 65 in the third round of the Alabama-based event. The world No.3 did not drop a shot at the Robert Trent Jones Golf Trail course on Saturday to move up from a tie for 11th into the outright lead on 15 under with one round to play. Sarah Jane Smith is the pick of the Australians, five shots adrift in equal sixth spot on 10 under while countrywoman Katherine Hull is well off the pace on two under. Smith started the day tied for 21st place and moved quickly through the field with three birdies in the front nine, including two in a row starting on the 8th hole. The 28-year-old Australian moved to 10 under overall with a birdie on the 11th hole but despite scoring two more birdies for the day, bogeys on the 12th and 17th meant Smith remained five shots behind Lewis. Lewis began with two birdies before making it four from five holes in an impressive start to her round. The 27-year-old American added birdies on the 9th, 11th and 16th holes to take top spot on the leaderboard with compatriot Angela Stanford two shots back. Stanford stormed home with three birdies in the last five holes and could have been tied for second with Lizette Salas but for the 23-year-old American bogeying the last hole to drop to 12 under for the tournament. Overnight leader Lexi Thompson had a shocking third round, bogeying the 6th and 13th holes, plus she slumped to a double-bogey on the par-four 12th. The 17-year-old dropped to a tie for sixth, alongside Smith and Hee Young Park of South Korea at 10 under. South Korea&aposs Haeji Kang and Mi Jung Hur sit just ahead of that group on 11 under. World No.1 Yani Tseng sits 10 shots off the leader after her second straight two-under round of 70.