Rockstar Makita Suzuki's Ryan Dungey won the $1,500 Progressive Holeshot Award to open the AMA Supercross class main event. Following Dungey through turn one was Torco Fuels Honda's Kevin Windham, with championship leader Chad Reed fifth.
On lap three Hill moved past Dungey for the lead and began to pull away. Reed, who rides for Team San Manuel Yamaha, moved into second place and on lap eight, while on the back wheel of Hill, he crashed and re-started in ninth place.
Hill went to take a shock win, ahead of fellow rising star Dungey, with Windham in third.
"Getting second was amazing a few races ago," said Hill. "I do not know how to put it into words this win. The season has had its ups and downs, but this is huge for me. Yamaha put faith in me, and I am grateful for that."
Dungey, who competes in the Western Regional AMA Supercross Lites class championship, moved up to compete in the AMA Supercross class and finished second. Tonight's race, before his hometown crowd, was his best finish since moving into the premier class.
"I ripped out of the gate tonight and had a good lead," said Dungey. "The crowd was behind me 100%, and I could hear them on every lap. This is only my third race in this class, so I very happy."
Reed, who had been battling an energy-sapping illness at the eleventh round of the series, finished seventh.
"This is a disappointing outcome after I was setting myself up to take the lead," said Reed. "I had to sit out the final practice and haven't felt well all weekend, so to be in the position to potentially win this race was very positive.
"I felt as though I had enough to hang on and win this, so seventh is little reward. It also hurts in terms of the championship, though I am lucky in a sense that Windham didn't take maximum points."
Reed now holds a 17-point lead over Windham with six rounds to go.
In the Eastern Regional AMA Supercross Lites class main event, Pro Circuit Kawasaki superstar Ryan Villopoto finally won his first race of the season.
Torco Fuels Honda's Josh Grant, of Riverside took the Progressive Holeshot Award, leading Villopoto through turn one. Grant held the lead until lap six when they traded positions for the number-one position.