Dufner, seeking his first PGA Tour victory, finished the day at 17-under 199 -- two shots clear of Canadian Graham DeLaet.
Dufner will need to overcome some history to claim the win, however -- he was ahead by a stroke after 36 holes at the Masters this month but ballooned to 150 over the following two days to fall out of contention.
DeLaet carded a 6-under 66 Saturday, finishing at 15-under 201 at TPC Louisiana.
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