Villopoto, of Poulsbo, Wash., has the upper hand going into Saturday's 10th of 17 events at Lucas Oil Stadium. The 22-year-old factory Kawasaki rider has four victories including the past two and a 196-173 points lead over Stewart.
"It's gone well for sure and it's nice to have that 23 points, but I need to get out there and win some more races," Villopoto said. "I don't think I can ride conservatively and go through the motions. As long as I'm winning races, I'll be in position to win the championship when it comes to Las Vegas (season finale)."
Villopoto doesn't feel comfortable enough to cruise because, in the opinion of many, the top talent runs deeper this season than it ever has since the AMA formed the Supercross series in 1974.
"We've never had a season like this one for the fans," Villopoto said. "It's usually been two guys, not five, battling for the championship. It's definitely good for the sport."
Reed, the 2004 and 2008 Supercross champion, has 172 points and Dungey has scored 165. Trey Canard is fifth with 154. Even with a tight point system that awards 25 to win, 22 for second and drops two points for each position through fifth and one from sixth to the 20th and last rider in the main event, Villopoto can't afford to settle for a string of top-fives.
Stewart, 25, is capable of dominating and is the biggest threat to overtake Villopoto. He had 11 victories in 2009 and 13 in 2007, winning the championship both seasons. Reed has titles in 2004 and 2008, but his forte has been a steady stream of top fives. Stewart missed the 2008 season with an injury and Ricky Carmichael, winner of five of six Supercross titles from 2001 to 2006, missed 2004 with an injury.
Australian Reed has a victory at San Diego this season, was runner-up last week at Daytona and Oakland and has been seventh or better in the nine races.
Dungey, a factory Suzuki rider, won six races in becoming the second rookie to take the Supercross championship, but he's winless this year. He doesn't figure to stay that way for 17 events. The 21-year-old from Belle Plaine, Minn., has four second-place finishes, three third and a fifth. He took a big hit in the points in the second event at Anaheim, dropping out with a mechanical failure and finishing 20th.
Stewart and Reed were injured early last season when they crashed into each other and missed the rest of the season. Stewart broke his wrist and Reed his hand.
Villopoto had won twice in Supercross in his rookie season of 2009 and was chasing down Dungey last season. Villopoto had won seven of 11 main events including at Indianapolis and closed the gap to 12 points with four events remaining. At St. Louis, Villopoto crashed and broke his right leg and ankle. He rides with five plates and 12 screws in it.
In the season opener at Anaheim on Jan. 8, Villopoto took over the lead on the opening lap and led the rest of the way. He also won at Dodger Stadium in Los Angeles, Atlanta's Georgia Dome and Daytona, has finished second to Stewart and Anaheim II and was third at Houston.
"The opener at Anaheim was a great race to win, for sure," Villopoto said. "But I knew I wasn't going to lose anything. The only thing you lose is endurance and being in shape. I was off the bike for five months, but my preparation and being really ready physically was the best it had ever been. My speed has gotten better this season.
"I've always been on the same level as those guys (Stewart, Reed, Dungey), but I ended up getting hurt."
Stewart has wins at Phoenix, Oakland and Anaheim II and four more top-fours. He finished 15th at Houston after getting collected in a first-lap, first-corner crash, and he crashed on his own from the lead at Daytona.
Stewart was leading going into the final lap at Atlanta, but arch-rival Reed tried to pass him and they made contact and went down. Villopoto drove past to win. Reed recovered to take third and Stewart was fourth.
"It was a gift and I'll take it," Villopoto said.
At Daytona, Stewart had a six second lead, but missed a long jump and crashed hard over the handlebars. With the help of course workers, he was able to remount his Yamaha and salvage ninth.
Villopoto took over the lead when Stewart crashed and won.
"I was out there riding fast, as hard as I could really," Villopoto said. "When I saw the way he (Stewart) went out there, I kind of figured it wasn't going to last. I was riding my own race and whatever was going to happen was going to happen. The Daytona race is a lot longer (in minutes, because of the length of the track) than a normal Supercross and I know the end of the race counts, not the beginning."
Canard, a factory Honda rider, had the first win of his Supercross career at Houston.
Supercross, which uses 450cc motorcycles, will be joined by the Supercross Lites Eastern Regional Series, which race on 250cc bikes. It will be the fourth event of the season for the Lites. Blake Baggett, of Grant Terrace, Calif., Justin Barcia, of Ochlocknee, Ga., and Dean Wilson, of Menifee, Calif., each have one victory in 2011.
Practice and qualifying begins at 12:30 p.m. and the main event begins at 7 p.m. Saturday.