Hanson had three bogeys in a five-hole span but rallied for a 2-under-par 70 in the third round. He's at 16-under 200 after 54 holes, one stroke ahead of Rory McIlroy.
George Coetzee shot 6-under 66 Saturday and moved into third at 13-under. Luke Donald is in a group of six players tied for fourth at 11-under. All six shot either 68, like Donald, or 69 in the third round.
Hanson and McIlroy, playing in Saturday's final group, both posted birdies at the second hole but McIlroy had a bogey at the par-5 third, allowing Hanson's lead to get to three strokes.
Hanson, though, had bogeys at Nos. 4 and 5 and then another at the eighth hole to drop into a tie for first. He pulled back ahead with a birdie at No. 9. Both he and McIlroy played the second nine in 3-under with McIlroy's birdie at 16 cutting the lead to one.
Two of Hanson's birdies came at 13 and 15, both par 5s. He's 6-under on those holes and 10-under on all par 5s for the tournament.