Schedl GP Racing rider Philipp Oettl secured a career first pole - also his first front row start - by setting a succession of fearless, fastest laps on the drying track, before a downpour made his time untouchable for pole in the Moto3 qualifying session in Austin.
The 19-year-old KTM rider and his small team, managed by his racer father Peter Oettl, took no chances and made sure of setting strong laps amid changeable weather, with the German showing his skill as he repeatedly slashed his time down to the session best of 2m 18.398s, which stayed put at the top of the timesheets when the rain arrived with twenty minutes of the session still to run.
The rest of the front row is an all Honda affair with Estrella Galicia 0,0 rider Jorge Navarro, who set the best time of the weekend in practice, too realising that a fast early lap was important and on noticing that Oettl was running away with the session posted a time just over half a second behind as the rain arrived.
Gresini's Enea Bastianini completes the front row at the Circuit of the Americas.
Fourth went to Jakub Kornfeil and the rapidly improving Drive M7 SIC team, their other rider Adam Norrodin was the top rookie securing sixth on the grid in the tricky conditions and is well placed for another podium push after his disappointing finish in Argentina.
The pair are split by Sky Racing Team VR46 rider Romano Fenati, who did not allow the rain to stop his much improved qualifying run so far this season in fifth.
Leopard Racing rider Andrea Locatelli starts sixth, Ongetta-Rivacold rider Jules Danilo seventh, with the second Leopard entry in the top ten, piloted by last years race runner-up Fabio Quartararo in ninth.
Livio Loi consolidates his solid start to the season by completing the top ten on the grid for RW Racing GP BV.
Current championship leader Brad Binder sat in the pits watching how the other riders were managing the drying track and lost out by not setting a banker lap, leaving him with work to do in twelfth for Red Bull KTM Ajo.
The conditions appeared to benefit Britain's sole Moto3 representative as John McPhee scaled the timesheets for 17th on the grid for the Peugeot MC Saxoprint team.
Several other big names were caught out by the sudden change in weather with only Gabriel Rodrigo making any real progress as the majority of riders returned to the track for the final five minutes in search of improvements, gaining seven places for 24th on the grid.
Those making no ground on their returnand starting down the grid include both previous race winners- Qatar victor Niccolo Antonelli sits in 30th and Argentina winner Khairul Idham Pawi in 32nd.
Falling as the rain hit were Team Italia's Stefano Valtulini and Karel Hanika, the Mahindra rider, who walked away holding his wrist, also had his previous fasted lap chalked off for exceeding track limits.