Keegan Bradley, trying to win the Byron Nelson Championship for the second time in three years, fired a two-under 68 to cling to a one-stroke lead over South Korea's Bae Sang-Moon.
In windy conditions at the par-70 TPC Four Seasons Resort course, Bradley closed with a bogey for the third round in a row but the American still stood atop the leaderboard on 13-under 197 with Bae on 198.
Nathan Green was the best-placed Australian, firing a two-under 68 to head into the final round six shots off the pace.
Fellow Australians Marc Leishman and Cameron Percy were two shots further back on 205.
Jason Day fired five birdies on his way to an impressive four-under 66 to surge 49 places up the leaderboard and finish the round on 206. Stuart Appleby was one stroke behind on 207.