Windham was putting on a clinic out front in the beginning of the race, but eventually started losing a lot of ground to the riders behind him, who were jumping the track's triples while he wasn't.
Davi Millsaps was the first rider to catch and pass Windham, and he led for two laps before tossing it away while out front.
Chad Reed (22) took over the lead after Millsaps went down, and Windham (pictured, right of frame) went down in this maneuver over the track's third-base-line triple and went off the track.
Jacob Marsack was the talk of the main event, finishing fourth behind Reed, Windham and Millsaps.
Most of the riders spent some time sprawled out on the track like Ivan Tedesco here. Tedesco's fall here was on the last lap and cost him fifth place. Langston took fifth, Tedesco was sixth, and Nick Wey - the last rider on the lead lap - was seventh.
Reed celebrated his third victory of the season and extended his points lead to 19 over Windham with 13 rounds still left to run.