Drewitt added a 3-under 68 to his opening 67 to be 7-under at the halfway mark at Fox Den Country Club in Tennessee and four behind the lead being held by American Derek Ernst.
One of six Australians in the field, Drewitt is the only one inside the top 20 and will start the weekend in a share of fourth place.
Australian Open champion Cameron Davis has also made the cut with scores of 70-69 having him 3-under-par and T23, one ahead of Rhein Gibson who is T34.
Western Australian Curtis Luck, who opened with 68 to be among the top 10, slumped to a 75 on day two and will miss the cut as will Jamie Arnold and Stuart Appleby.
It was a slow start for Drewitt who made one birdie and one bogey in his opening nine to make the turn even par but things got interesting on theinward journey.
He made an eagle at the par-5 10thto et the tone then backed up with further birdies at 12 and 14.
While he dropped shots at 15 and 17 a birdie at the last was a positive note to finish one and he will head to Saturday with plenty of confidence.
For Curtis Luck it was a disastrous day despite starting with two birdies in his first five holes.
Playing the back nine first he made the turn 1-under but it was a roller coaster around the front nine.
He made bogey at the first but added an eagle at the fifth then gave both shots back immediately with a double bogey at the sixth.
But the worst was yet to come as the 21-year-old wracked up a quadruple bogey eight at the penultimate hole to ruin his week.
RULES - GRASS COVERED AREA IN BUNKER:
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