Windham wins Unadilla, Stewart injured.

Unadilla, round six of the AMA Toyota Motocross Championship Presented by FMF, marked the first round without reining champion Ricky Carmichael - riding a partial 2007 season before retirement.

RC had won all five of the opening rounds, with Stewart his only real rival, but the Kawasaki star was unable to collect what was expected to be a relatively easy Unadilla victory after being injured in morning practice, marking the latest in a series of Unadilla accidents for the Floridian. Stewart will have his head and back evaluated by his doctor this week and his status is still uncertain for next week's race.

In the AMA Supercross champion's absence, Honda rider Windham opened the day with a win in the first moto and followed it up with a third place finish in race two - behind Stewart's team-mate Tim Ferry and Honda's Andrew Short - to take the overall, the 28th of his career.

"I've been known through my career to have a lot of throttle control, which you need at this track," said Windham. "I come into some of these hard-packed tracks with added confidence. I was riding behind Andrew [Short] and we were kind of closing in, but toward the end I kind of broke out the calculator and started doing the math and knew I could get the win."

Ferry's 5-1 finishes gave him second overall, with Short third after 6-2 results. KTM's Mike Alessi was second in moto one, in which Yamaha's Grant Langston was third, but both failed to replicate that form in the second race.

In the Motocross Lites class, Ben Townley took the overall - and joint championship lead - after Kawasaki team-mate and reigning champion Ryan Villopoto suffered a mechanical problem in race one. BT won that moto, then fought back from a fall to take third in race two - which Villopoto won from Suzuki's Ryan Dungey.

The AMA Toyota Motocross Championship heads west next weekend to Lakewood, Colorado.