Austin MotoGP: Marc Marquez on pole after sprint for spare Honda

Marquez had secured provisional pole by three tenths of a second early in Q2, but then struggled to restart his bike in the pitlane before the second runs.

That proved the precursor to a more serious problem, as a warning light appeared on his Honda coming out of the final corner just as he was about to start his flying lap.

Marquez parked the bike next to the pitwall and sprinted down to the Honda garage, leaping onto his spare with just enough time to charge round on a rapid out-lap before the chequered flag.

By that time he had been elbowed down to seventh place as provisional pole changed hands repeatedly between Cal Crutchlow, Jorge Lorenzo and Andrea Dovizioso.

Marquez immediately beat Dovizioso's pace in sector one, survived a mistake in sector two and pulled together the rest of the lap to do a 2m02.135s and deny Ducati a second straight pole by 0.369s.

Lorenzo held on to the final front row spot ahead of Yamaha team-mate Valentino Rossi, who pushed Crutchlow's LCR Honda back to fifth.

Crutchlow starts alongside fellow Honda-riding Brit Scott Redding, as the Marc VDS rider achieved a MotoGP career-best sixth on the grid.

Qatar Grand Prix podium finisher Andrea Iannone had to use up tyres coming through Q1, and although he briefly held second on the grid to Crutchlow during he late flurry, he fell back to seventh on the second Ducati.

Suzuki's Aleix Espargaro also spent a spell on the provisional front row but ended up eighth. His brother Pol and Tech 3 team-mate Bradley Smith completed the top 10.

Both Suzukis reached Q2, as Maverick Vinales was second to Iannone in Q1. Vinales could not make much ground in Q2, where he was 12th behind Danilo Petrucci on the lead Pramac Ducati.

While it was the two factory bikes in Q1 that eventually earned the available Q2 spots, Avintia's Hector Barbera came very close to bringing a second private Ducati into the pole shootout to join Petrucci.

The Spaniard missed out by just 0.048s when Vinales popped in his late lap.

Dani Pedrosa's stand-in Hiroshi Aoyama has made little impression all weekend on the second works Honda after his call-up from test duties. He will start 18th.

The home crowd had little to cheer as Nicky Hayden - the only American racing in any of the three grand prix classes - struggled to 22nd, seven tenths and five places behind Aspar team-mate Eugene Laverty.

Follow the Austin MotoGP race day as it happens with AUTOSPORT Live from 5pm UK time on Sunday - MotoGP race from 8pm

STARTING GRID: