Hudson Swafford opened up a two-stroke lead at the halfway mark of the Corales Puntacana Resort and Club Championship on Friday.
The American fired a five-under 67 in the second round in the Dominican Republic to move into 12 under.
Swafford, who has missed six cuts in 11 events this year, mixed seven birdies with two bogeys to be on track for a second PGA Tour win and first since 2017.
He is two shots clear of countrymen Sean O'Hair (67), Luke List (65) and Justin Suh (67).
Runner-up last year, Mackenzie Hughes is again in contention after shooting a 67 to be tied for fifth at nine under.
The Canadian is alongside Adam Long (65), Zhang Xinjun (69) and Sepp Straka (70).
Straka had shared the overnight lead with Swafford, Tyler McCumber and Scott Harrington, the latter duo slipping even further back after shooting 71 and 74 respectively.
Defending champion Graeme McDowell missed the cut after backing up his opening-round 70 with a one-over 73.