Honda's Marc Marquez will start Sunday's MotoGP race at Austin from fourth on the grid after a penalty for blocking Yamaha rider Maverick Vinales in qualifying.
Marquez was placed under investigation at the end of qualifying for blocking Vinales at the tight left-hand Turn 15 while the Yamaha man was on a hot lap.
The reigning champion had provisionally scored his sixth successive pole at the Circuit of the Americas after beating Vinales - who regrouped to set the second-fastest time - by 0.406s.
While Marquez's 46th premier class pole will stand in the record books, the stewards have elected to demote him to fourth place on the grid.
This promotes Vinales to the top spot for the first time since last year's Aragon race, ahead of Andrea Iannone's Suzuki and Johann Zarco's Tech 3 Yamaha.
KTM rider Pol Espargaro was also handed a three-place penalty for blocking the Marc VDS Honda of Thomas Luthi in Q1, and drops from 12th to 15th on the grid as a result.