The AMA Motocross Champion took Yamaha's 17th success at the venue and also increased his personal triumph tally to 27; equalling Bob Hannah in 5th place on the all-time victory roll.
Despite the impressive numbers Anaheim II was a hard meeting for the 23 year old. He collided with Travis Preston during practice and badly cut his hand, he then admitted that he made mistakes and wasn't riding well during the race that was watched by over 43,000 people.
On a track that was not easy for overtaking Stewart needed half of the 20 laps to pass Ivan Tedesco, Ryan Villopoto and then impressive Rookie and fellow Yamaha rider Josh Grant. Two circulations later and he demoted Kevin Windham for the lead and would hold the advantage to the chequered flag. Chad Reed had recovered from a first corner crash to make his way to second place, therefore limiting Stewart's points gain in the standings. Grant held on for fifth place and has yet to drop out of the top five in the first three events.
"It was a tough weekend for me as far as getting adjusted to the track," Stewart admitted. "Also, physically, it was definitely tough for me. But if we can get wins like this, I can't imagine what it will be like when things go smoothly; maybe we can do even better."
Stewart is now up to fourth in the series, 12 points from the top, while Grant is second and just 3 points from reigning champion Reed.
Round 4 takes place next Saturday at the Reliant Stadium in Houston, Texas.