The 450 Main was an intense battle throughout the top 10. Ken Roczen grabbed the holeshot with Marvin Musquin and Cooper Webb following closely behind. Cooper made his way around Marvin and Chase Sexton would follow. Then Chase gained significant ground on Ken through the whoops, making the pass and leading the race. Eventually, Ken would run out of steam, falling through the pack and allowing Cooper and many more opponents to make passes. Cooper Webb made the pass on Chase Sexton after Chase made a mistake through a turn, grabbing the lead. Cooper would lead the rest of the race, win, and become the 2021 Monster Energy Supercross 450 champion