US Grand Prix: Mercedes' Nico Rosberg claims pole in rain-shortened qualifying

Austin: Nico Rosberg will start the United States Grand Prix from pole with Mercedes team-mate Lewis Hamilton alongside him following a curtailed rain-lashed qualifying session at the Circuit of the Americas on Sunday morning.

The session, re-scheduled after being postponed on Saturday, was cut short after only two of the normal three sessions, as conditions worsened.

Rosberg, who was quickest in Q2, became the pole-sitter after a 15 minutes break during which the organisers decided it was impossible to continue.

It also meant German Rosberg grabbed his best chance to claim another victory and keep alive his title challenge on a day when defending two-time world champion Hamilton will seek to win and clinch his third drivers' title.

Australian Daniel Ricciardo of Red Bull was classifed in third place ahead of his team-mate Daniil Kvyat with four-time champion Sebastian Vettel fifth for Ferrari.

Vettel will take a 10-place grid penalty, however, after taking a new Ferrari power unit this weekend.

Sergio Perez of Force India was sixth, but will be elevated to fifth to line up alongside his team-mate Nico Hulkenberg ahead of Felipe Massa of Williams, Dutch teenager Max Verstappen of Toro Rosso, Fernando Alonso of McLaren and Valtteri Bottas in the second Williams.

Kimi Raikkonen had qualified in fifth for Ferrari before he also took a 10-place penalty.

After two days of torrential rain and electrical storms with lightning, the teams were lining up to leave pit lane as soon as the track opened for action at 0900 local time (1400 GMT) on another dismal morning in Texas.

"Conditions are really limit," said Frenchman Romain Grosjean to his Lotus team, as spray plumed from the cars, all running on full-wet tyres.

"We expect the first 10 minutes to be the best weather," a Force India technician told Mexican Sergio Perez. "It's very dark," complained Raikkonen.

In such conditions it was clearly imperative to record an early lap time in case the session was curtailed. Maldonado did so with 2:04.716 before times tumbled and Hamilton, with 1:59.393, moved eight-tenths of a second clear of the field.

Within seconds, Spaniard Carlos Sainz lost control and crashed at Turn Four, wrecking the front of his car to leave Toro Rosso with a major repair job just five hours ahead of the race.

It was his second crash at successive events, following his high-speed accident in Russia from which he was lucky to escape unhurt, and resulted in a red flag stoppage.

At the time, Hamilton was on top ahead of Ricciardo and Kvyat, but both Ferrari drivers had failed to clock a lap.

"It's just as wet out there as it was yesterday," said Hamilton.

The session resumed after a 10-minute break with Rosberg jumping briefly to second in marginally improved conditions, four-tenths adrift of his team-mate, before Hamilton responded by slicing 1.3 seconds off his previous best lap.

Rosberg then went top before Vettel, saddled already with a 10-place grid penalty for taking a new power unit, glanced the wall in a spin at Turn 10 and pitted, Ricciardo responding with a 1:57.163. Hamilton, in traffic, was third, but regained control in 1:56.871.

"People are getting quicker, Nico, we need to keep setting times," Mercedes told Rosberg as the action turned frantic as everyone lapped fast in a bid to beat the weather before the flag.

When it came, it meant an early exit for Sainz, at the back, along with the two Manor Marussia men Will Stevens and American Alex Rossi, in 19th and 18th respectively and Felipe Nasr and Marcus Ericsson, in the two Saubers on the day the team celebrated their 400th Grand Prix entry.

In Q2, Hamilton and Rosberg soon topped the times before Hulkenberg spun at Turn 10, followed by Button, Verstappen and Kvyat as the rain intensified, Rosberg holding the ascendancy.

Hamilton then completed a full 360-spin at Turn 10, as did Raikkonen, both men showing phenomenal car control to catch their cars.

"They are red flag conditions," said Vettel as it ended with Rosberg on top and Alonso, Bottas, Grosjean, Button and Maldonado missing the cut.