Following a dramatic, tense, action-packed and ever-changing season finale – all terms which seemed to define the 2015 Pirelli World Challenge season – Johnny O’Connell has retained his crown in GT after a roller coaster, 50-minute season finale at Mazda Raceway Laguna Seca.

It’s O’Connell’s fourth consecutive championship and first in the new Cadillac ATS-V.R, which made its competition debut this year.

O’Connell finished 12th in the No. 3 Cadillac Racing Cadillac ATS-V.R, surviving apparent contact with chief title rival Olivier Beretta at the Corkscrew on Lap 25 that dropped him from third to 14th, but making it home to the finish.

Beretta meanwhile, who had made it up to third after starting 12th in the No. 61 R. Ferri Motorsport Ferrari 458 Italia GT3, was issued a drive-through penalty for avoidable contact. He resumed on track ahead of James Davison’s Nissan GT-R NISMO GT3 after he served his penalty.

Beretta was down in points after he’d served his penalty; when he ran seventh, he had 1671 points and with O’Connell 14th at the time, O’Connell had 1673.

But Beretta’s chances came to an end shortly thereafter. Running ahead of Peter Cunningham’s Acura TLX-GT, Beretta then pulled off with just over five minutes remaining at Turn 11, retiring from the race.

Unofficially, O’Connell beat Beretta 1679-1618, as the points table was often closer than that throughout the race.

The NGT Motorsport pair of Ferrari 458 Italia GT3s finished 1-2 overall, Alessandro Balzan claiming the win ahead of Alessandro Pier Guidi.

Balzan got the jump in his chrome No. 29 car from second on the grid ahead of polesitter Pier Guidi in the red No. 30 car, and never looked back from there.

Pier Guidi finished second after getting around O’Connell on Lap 7, and trailed home his teammate by 2.76 seconds.

Ryan Dalziel finished third overall in the No. 31 EFFORT Racing Porsche 911 GT3 R, in that car’s final race before EFFORT upgrades to two new 991-based Porsche 911 GT3-Rs for 2016.

Andy Pilgrim finished a season-best fourth in the second Cadillac Racing Cadillac ATS-V.R, with Michael Lewis ending his first year in the championship fifth in the second EFFORT Racing Porsche 911 GT3 R.

Eric Lux (GTA) and Colin Thompson (GT Cup) also claimed class victories. For Lux, in eighth overall, it marked his best result of the season and first win in 2015 in the No. 08 DragonSpeed Mercedes-Benz SLS AMG GT3.

Thompson’s win came after a mid-race pass on Lap 20. As Beretta moved up to fourth, and O’Connell sliced past Thompson and Alec Udell, Udell left the inside lane open at Turn 2 and Thompson moved past to secure his 13th win in 18 races in the No. 11 Kelly-Moss Motorsports Porsche 911 GT3 Cup.