Arjun Atwal rode on a brilliant back-nine to card a three-under 69 and surge to the tied 31st spot but Jeev Milkha Singh slipped to tied 51st with a modest 72 in the second round of the Turning Stone Resort golf Championship in New York.
Atwal has a two-day total of four-under 140, while Jeev is two-under 142 overall.
Orlando-based Atwal played out a roller-coaster front nine which he opened with a birdie.
A bogey on the second hole followed by another on the fourth pegged him back before Atwal recovered to gain a shot on the fifth.
But a dropped stroke on the ninth left him even-par at the turn.
On his way back, Atwal went on a birdie-firing spree, sinking in five in the space of seven holes to end the day on a high.
Jeev, meanwhile, picked up a bogey and a birdie in his largely subdued round.
At the top, American Vaughan Taylor led by a stroke after a second successive 67 took his total to 10-under 134.