The 14-time Major-winner, who has surged back to world number two after a damaging sex scandal and injury, dropped shots on eight and nine but recovered to card 66 on the par-71 course, trailing leader Troy Matteson.

On a hot, humid and low-scoring day, Matteson's scorching 63 was only good enough for a one-shot lead over Brian Harman, Jeff Overton and Robert Garrigus, with Gaganjeet Bhullar and Tom Gillis one more back on six-under.