Michael Thomson shot a 7-under 64 on Saturday for a share of the third-round lead with Scott Stallings in the Web.com Tour Finals' Albertson Boise Open.
Stallings, a three-time winner on the PGA Tour, had a 66 to match Thompson at 16-under 197 at Hillcrest in the second of four events that will determine 25 PGA Tour cards for next season.
Argentina's Miguel Angel Carballo was a stroke back after a 67. England's Andrew "Beef" Johnston, the second-round leader after a 63, was fourth at 14 under after a 70.
The series features the top 75 players from the Web.com money list, Nos. 126-200 in the PGA Tour's FedEx Cup standings -- Stallings was 128th, Thompson 145th, and Carballo 187th -- and non-members such as Johnston with enough PGA Tour money to have placed in the top 200 in the FedEx Cup had they been eligible.
The top 25 players on the Web.com regular-season money list earned PGA Tour cards. They are competing against each other for tour priority, with regular-season earnings counting in their totals. The other players are fighting for 25 cards based on series earnings.