Following Frisselle's incident, the race ran caution-free until the #30 Mazda RX-8 of Dane Cameron stopped at turn nine entering the race's final half hour.
David Donohue led 13 laps in the #58 Brumos Porsche Riley before contact with a GT car resulted in a cut tyre and a tenth-place finish, while Rojas, Valiante and Mark Wilkins also completed at least one lap at the front.
In the Acxiom GT class, Stevenson Motorsports stretched the opening shifts for both Andrew Davis and Robin Liddell, who had fresher tyres in the stretch en route
to a second victory of the campaign.
Liddell won over SpeedSource's #70 Castrol Syntec Mazda RX-8 of Nick Ham and Sylvain Tremblay, while Paul Edwards and Kelly Collins took third in the #07 Pontiac GXP.R, followed by Joe Foster and Charles Espenlaub, who gave the #40 Dempsey Racing entry its best finish to date.
"Nick kept me honest in the closing laps because he could match our times," Liddell admitted, "but, honestly, I knew we had it in the bag."
Liddell led 60 laps and Davis 14, while defending race co-winners Ham and Tremblay led 14 and four laps respectively. The only other leader was polesitter and point co-leader Leh Keen, who led the opening eleven laps in the #87 Farnbacher Loles Racing Porsche GT3.
Keen and Dirk Werner placed fifth after winning the past three GT races and four of the last five. They maintained their points lead over Edwards and Collins, but saw the gap close to 25 points with four events remaining. Tremblay and Ham moved from fifth to third in the standings with 211 points.