But her run screeched to a halt with three straight bogeys from the 13th hole at the Seaview Bay Course.
Thompson, playing ahead, pounced, making the only eagle of the day at the par-five 18th, where she holed a 15-foot putt for a four-under-par 67.
That left Lee, who attaches a '6' to her name to differentiate herself from five other Korean professionals with the same name, also needing to eagle the 18th to force a playoff.
Lee eagled the hole on Saturday but was unable to replicate the feat, after a mediocre second shot left her 40 feet from the cup, and had to settle for a two-putt birdie.
Thompson finished at 12-under 201 for her 11th LPGA victory.
Lee (70) was alone on 11-under, with American Ally McDonald another two shots back in third place.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Ken Ferris)
