Reigning MotoGP champion Marc Marquez maintained his perfect qualifying record at Austin after a thrilling shootout with points leader Maverick Vinales.
Marquez and Vinales were in a league of their own, the former narrowly prevailing after the chequered flag with a 2m02.741s effort.
This means Marquez remains unbeaten in qualifying at the circuit, the Honda rider having taken his fifth consecutive pole at the venue since it joined the calendar in 2013.
The best lap of the weekend belonged to Vinales heading into the Q2 shootout, but Marquez bettered that with his very first time, setting the benchmark at 2m03.675s.
His next effort lowered the target time to a 2m03.042s, with Vinales - who was visibly irritated by a run-in with Yamaha team-mate Valentino Rossi at Turn 18 - ending his first run almost nine tenths adrift.
However, the championship leader made huge strides in the second run, making up almost the entirety of the gap with the first lap, crossing the line 0.083 seconds off Marquez.
The chequered flag followed, with both Marquez and Vinales running ahead of provisional pole in the first half of the lap.
Vinales arrived first, clocking in a 2m02.871s to take top spot, but a last-gasp lap from Marquez allowed him to edge back ahead by 0.130s.
Rossi, who had been eighth after the first sequence of laps, ended up taking the remaining front row spot, finishing nine tenths off pole with a late effort.
Marquez's team-mate Dani Pedrosa leapfrogged Tech3 Yamaha's Johann Zarco late to finish fourth, while Ducati's Jorge Lorenzo completed the second row in sixth.
The three-time champion had been consigned to Q1 by a late shunt in the third practice session and was close to missing out on the top-12 shootout entirely.
He was two tenths off pacesetter Jack Miller after his first run in Q1, and couldn't improve on his time for the remainder of the segment.
At the flag in Q1, Lorenzo ended up more than half a second ahead on nearest rival Danilo Petrucci (Pramac Ducati), but his time looked under threat by Loris Baz.
That was until the Avintia Ducati rider took to the ground on exit out of the final corner, somehow hanging on to the bike yet losing his chance to advance.
Slotting in right behind Lorenzo in Q2 was team-mate Andrea Dovizioso, regrouped from a fourth-practice session plagued by electrical problems.
Tech3's Jonas Folger and LCR Honda's Cal Crutchlow - who crashed late in the session - join Dovizioso on the third row.
Capping a day that had started with a 10 falls from eight riders in third practice, qualifying had a number of incidents itself.
It kicked off with back-to-back shunts for the Espargaro brothers in Q1 - Aprilia's Aleix going down at Turn 1 and KTM's Pol soon following suit at Turn 2.
They will start at the back of the field, Aleix Espargaro failing to record a time following a mechanical problem in fourth practice, while Bradley Smith was the best of the KTMs in 18th.
Suzuki's Andrea Iannone and Marc VDS Honda's Jack Miller then crashed early in Q2, the pair to start 11th and 12th.