In the premier class, it was Honda HRC’s Chase Sexton (heat one) and Ken Roczen (heat two) taking the 450SX heat race wins. When the gate dropped on the main event, it was Roczen and Sexton who picked up right where they left in the heat races as the duo lead the field. Roczen led but his younger teammate was keeping pressure on the #94 for the first handful of laps, and Sexton appeared destined to earn his maiden 450SX win. However, a slight underjump threw off his entry to a turn and he went straight into a Tuff Block at the back of a steep, 180-degree berm. Sexton remounted in third behind Adam Cianciarulo (racing with a shoulder injury) but then had another mistake that cost him a handful of positions in the whoops. Still, Sexton gained several positions back—he passed Dylan Ferrandis, then got two spots from a collision between Marvin Musquin and Malcolm Stewart that took them both to the ground, one after block pass from Justin Barcia that gave Jason Anderson a taste of the Anaheim dirt, and one from an injured Cianciarulo not putting up much of a fight and sliding wide—and suddenly the #23 was fighting for fourth with Musquin. With Sexton's mistakes, Roczen had an 11-second lead over 2021 450SX champion Cooper Webb and three-time A1 winner Justin Barcia. Roczen held on to win his fourth Anaheim 1 Supercross 450SX main event as Webb and Barcia rounded out the podium. Musquin just barely edged out Sexton for fourth place finish by 0.013 seconds! Eli Tomac finished sixth in his debut with Monster Energy/Star Yamaha Racing as Stewart, who finished seventh in his Rockstar Energy Husqvarna debut, immediately started yelling at Musquin after crossing the finish line. Injured Cianciarulo finished 11th, and Dylan Ferrandis finished 16th after stalling out once in the whoops, losing a handful of positions as his bike hesitated to restart, and then went off the track late in the race to drop out of the top 15.