Ryan Villopoto hits a home run in supercross

Ryan Villopoto outdueled James Stewart and Ryan Dungey to win the inaugural AMA supercross race at Dodger Stadium on Saturday night. It was Villopoto’s second win of the season.

Stewart held the early lead but spun and fell on the 11th lap, and Villopoto ended up winning on his Kawasaki by nearly five seconds over Stewart in the Monster Energy AMA Supercross Series’ 20-lap main event, the third race of the series’ 17-race season. Dungey was third.

There were 41,107 on hand for the first supercross race held in Chavez Ravine, it was announced. The ballpark’s seating capacity is about 56,000, though a few thousand seats along the foul lines, which were next to the track, were blocked off for safety reasons.

Stewart, 25, who wore a Dodgers jersey with his name on his back during the pre-race introductions, reached the main race the hard way in a tough preliminary heat. The field is divided into two eight-lap heats and the top finishers in each advance to the main event. It’s normally a formality for Stewart.

On Saturday, though, Stewart crashed into the cushion barriers that encircle the track and dropped to last place as the 20 riders raced through the first turn. He then had to storm through the field to finish fourth and qualify for the main race.

Stewart, who won the title in 2007 and 2009, and two-time champion Chad Reed, 28, had their 2010 seasons cut short when they were both injured in a crash in Phoenix. Their absence helped promote the fortunes of Villopoto, Dungey and other young riders in supercross’ top division. (Reed was seventh Saturday.)

Dungey, 21, captured the title as a rookie last year with six victories. Villopoto, 22, won a series-high seven races and was vying with Dungey for the championship until Villopoto broke his right leg in a crash.

But Villopoto bounced back by winning this season’s opener at Angel Stadium in Anaheim two weeks ago. Stewart won the second race, also in Phoenix, last weekend.

james.peltz@latimes.com