Spielberg (Austria) (AFP) - Valtteri Bottas upstaged both title protagonists on Saturday by claiming his second pole position for Mercedes in a tense qualifying session for Sunday's Austrian Grand Prix.
The Finn clocked a best lap of one minute and 4.251 seconds to outpace championship leader Sebastian Vettel of Ferrari by four hundredths of a second.
Briton Lewis Hamilton, who trails Vettel by 14 points in the title race, was third fastest in the second Mercedes, but will start the race from eighth on the grid due to a five-place penalty for an unscheduled gearbox change.
The session ended in some disarray when Frenchman Romain Grosjean stopped his Haas out on the track to bring out a series of yellow flags that prevented any final fast laps.
"I enjoyed it today and the car was getting better and better," said Bottas. "I had a decent lap and I am looking forward to Sunday ? and hope Lewis and I can do a great job for the team."
Vettel said: "I was hoping for the last run, but then it was a bit of an anti-climax with the yellow flags."
Hamilton said he was happy enough with third: "Of course, I would have loved to improve my lap, but it just wasn't meant to be today."
When asked after the session to shake hands, Hamilton and Vettel turned and walked away ? having done so earlier without television cameras.
It was Mercedes' 80th pole position and the 51st pole by a Finnish driver. For Hamilton, from eighth, it is a major challenge as he has never won from below sixth on the grid ? a feat he achieved at the 2014 British Grand Prix.
Finn Kimi Raikkonen, the 2007 world champion, will start from third in the second Ferrari ahead of Australian Daniel Ricciardo and his Red Bull team-mate Max Verstappen, backed by a crowd including 10,000 Dutch fans at the Red Bull Ring.
Grosjean was seventh ahead of Mexican Sergio Perez and his Force India team-mate Esteban Ocon, with Spaniard Carlos Sainz 10th for Toro Rosso.
- Hamilton's bright start -
The session began in balmy, but cloudy, conditions with a track temperature of 45 degrees, as Hamilton soon stamped his speed and authority on proceedings.
Eight minutes in, he clocked 1:05.238, three-tenths clear of Vettel.
Hamilton improved his time to 1:05.064, when Dane Kevin Magnussen had what appeared to be a suspension failure at turn three and drove his Haas gingerly back to the pits.
The first session ended with Hamilton on top ahead of Raikkonen and Vettel, with Bottas pushed back to fifth by a flying Sainz.
Out went Briton Jolyon Palmer of Renault, Brazilian Felipe Massa and his Williams team-mate Lance Stroll, Swede Marcus Ericsson and his Sauber team-mate Pascal Wehrlein.
For Williams, it was a huge disappointment after the introduction of an upgrade package that has brought no instant success.
Hamilton was out immediately for second qualifying on super-softs, a switch that signalled he may intend to run a long first stint in Sunday's race. His first lap was 1:04.800, trimmed by Bottas in 1:04.640 as the Mercedes topped the pile.
Vettel, on ultra-softs, grabbed second in the closing minutes as Hamilton warmed up a set of super-softs for his race starts, with the top three separated by only 0.160sec.
German Nico Hulkenberg of Renault, two-time champion Fernando Alonso and his McLaren team-mate Stoffel Vandoorne, Russian Daniil Kvyat of Toro Rosso and the luckless Magnussen, who did not run, were the five to bow out.
As the top-ten shootout began, Verstappen was first out.
He went top, only to be supplanted by Ricciardo and Hamilton, the only driver who will start the race on super-softs, before Bottas took control in 1:04.251.
Vettel then slotted into second again, and Grosjean's car failure ensured that Bottas took pole and his team-mate was to start eighth.