Louis Oosthuizen moved into the top ten as Jason Dufner continued to set the pace from Zach Johnson following the third round of the Crowne Plaza Invitational at Colonial in Texas.
Dufner and Johnson are set for a virtual match play finish as they both have several strokes on the rest of the field.
Last week’s US PGA Tour winner Dufner shot a third round of four under par 66 to give him a one stroke advantage over Johnson whose score for the day was 65.
With Tom Gillis the next closest player at seven under the winner on Sunday should come from the leading duo.
A victory for Dufner would create history as it would make him the first player in US PGA Tour history to win both North Texas events in successive weeks after his win in the Byron Nelson Championship.
Although Dufner led by two strokes at the start of the day things did not go all his way.
At one point he held a three stroke lead only to see Johnson close the gap in the final stages of the round, including birdies at the 16th and 17th.
The 2010 champion at Colonial, Johnson has now posted 15 consecutive sub-par rounds at the course and needed just eight putts in his first nine holes and a total of 23 for the day.
Former Open Champion Oosthuizen carded a two under par 68 to lie in a tie for seventh on four under, while Y E Yang moved to two under for the week with a 66.