Lingmerth followed up his 16th-hole eagle with a birdie on the next hole before play was halted. He was standing at 4-under through 17 holes and was two strokes clear at 12-under for the tourney.
Henrik Stenson, who won the event in 2009, held the advantage for most of the day, but stumbled to a pair of bogeys down the stretch. He stood at minus-10 through 15 holes when play was halted.
The low round of the day belonged to 49-year-old Jeff Maggert, who fired a 6-under-par 66 and was in the clubhouse at 9-under-par 207.
The third round, which was delayed 1 hour, 48 minutes by lightning, was set to resume 7 a.m. EDT Sunday.