Louis Oosthuizen fired a round of 64 to hold a share of the lead going into the final day of the Byron Nelson Championship.
The South African had a run of consecutive birdies on the 14th, 15th, and 16th to cap a superb round which moved him up 14 places on the leaderboard.
Overnight leader Brendan Todd did enough to retain a share of top spot, but needed a birdie on the 18th to do so after a bogey on the fourth saw him fall behind. He signed for a two under 68.
Oosthuizen claimed the best round of the day but James Hahn was one bogey on the 11th away from matching it, with a stunning run of birdies between the 12th and 16th catapulting him up to a share of third place alongside Gary Woodland and Mike Weir.
Woodland was in there despite a horror show on the par five fifth, where he got stuck in the sand and wound up with a double bogey.
Weir had an up-and-down round himself, with six birdies and two bogeys.
