Herfoss and his title rival, McMartin Racing Ducati's Josh Waters came into the meeting locked on points and faced a winner-takes-all fight for the crown.
The Honda CBR RR rider gained a one-point advantage by qualifying fastest – the only one to go under the 1:50 mark on the 4.9km circuit. Herfoss led throughout the first of the two 11-lap feature races. He went to the line 0.25s ahead of Waters.
“There was a lot of pressure. I rode the best I could and controlled the race from start to finish,” Herfoss said. Meanwhile Waters struggled under brakes but didn't want to blame that on his wrist injury.
On the final lap Cru Halliday (Yamaha YZF-R1-M) passed his Yamaha Racing teammate and 2022 champion Mike Jones to take third. “I had the worse start and felt it cost me the race,” said Halliday who was sixth at the end of the first lap.
Glenn Allerton (BMW M RR) finished fifth ahead of a fast-starting (and fourth early) Max Stauffer (Yamaha). Then followed Bryan Staring and Ant West on Yamahas, Broc Pearson (Ducati) and Ted Collins (BMW).
Herfoss led off the start of Race 2 before Waters took the lead into Turn 1. Stauffer went down shortly after, and Staring and Paris Hardwick (Kawasaki ZX10RR) also had issues.
Waters continued to lead until the sixth lap when Herfoss went under him at Turn 1. Two laps later Waters had the front end get away from him at Turn 6 and dropped the Ducati.
Herfoss was clearly ahead to the end and paid tribute to Waters who Herfoss said has made him the rider he is. “I ridden against him for half my life!”
On the last lap Halliday passed Jones to consolidate third in the championship while Allerton was fourth and West passed Pearson to take fifth. Next to cross the finish was Collins before a start penalty which elevated Mark Chiddo (Honda) to seventh. Arthur Sissis (Yamaha) and Waters completed the top 10.
Herfoss won the ASBK Championship by 20 points over Waters while Halliday was a point ahead of Allerton and five ahead of Jones. Yamaha took out the Manufactures Championship ahead of Ducati and BMW.