SPIELBERG, Austria - Mercedes driver Valtteri Bottas made a great start from pole position to win the Austrian Grand Prix on Sunday, while Ferrari's Sebastian Vettel finished just behind in second to extend his championship lead over main rival Lewis Hamilton to 20 points.

Bottas held off Vettel's late charge, with the German driver crossing the line just 0.6 seconds behind.

"He was catching up; I had a massive blister in the rear left tire)" Bottas said. "I was losing more and more stability, so I was happy the race ended on that lap."

Vettel was frustrated at missing out on a 46th career win by so little.

Mercedes' Valtteri Bottas (left) celebrates winning Sunday's Austrian Formula One Grand Prix in Spielberg, Austria with runner-up Sebastian Vettel of Ferrari. Dominic Ebenbichler / Reuters

"I was told he was in trouble, so I was pushing. The car came alive and I had really good pace," Vettel said. "I think I needed one more lap because he was really struggling up the hill."

Vettel had never finished higher than fourth in Austria, twice retiring from races.

"I really wanted to win, so I'm not entirely happy," Vettel said.

Meanwhile, Red Bull's Daniel Ricciardo showed great ability to defend third place from Hamilton, who almost passed the Australian driver on the last two laps but had to settle for fourth.

Bottas, who won in Russia, clinched the second victory of his career - and both have come since he joined Mercedes from Williams this season.

His first career podium was on the same Spielberg track, when he finished third for Williams in 2014.

Bottas is now only 15 points behind Hamilton in the overall standings and close to contending for the title.

"I believe and the team believes," Bottas said. "We're not even halfway yet."

Hamilton started from eighth on the grid on Sunday.

The British driver had the third fastest qualifying time behind Vettel and Bottas, but was demoted five places for an unauthorized gearbox change after the last race in Azerbaijan two weeks ago, which Ricciardo won.

Ricciardo, who is fourth overall, clinched his fifth straight podium.

At the start of the race, Fernando Alonso had to retire his McLaren after a collision caused by erratic Toro Rosso driver Daniil Kvyat.

Red Bull's Max Verstappen was slowed at the start by a clutch problem, which dropped him back in the field where he was collected by Alonso's out-of-control McLaren - the fifth time in the last seven races Verstappen has failed to finish.

Bottas got away cleanly but Vettel contested the start on his radio, saying Bottas had jumped the lights.

The Finnish driver was later cleared by stewards of any wrongdoing, and defended his lightning start.

"You are gambling between your reaction and guessing," Bottas said. "Sometimes you are a bit late and today was my best reaction to the lights."

Vettel emphatically disagreed.

"I don't want to take anything away from Valtteri, he drove an excellent race," Vettel said. "But I had a strong belief he had jumped the start. In my point of view his reaction time was inhuman."

Ricciardo backed up Vettel.

"The lights were held for a long time, more than normal. For sure he went, but the lights weren't out," Ricciardo said.

"I guess he got lucky, It was on the edge. I don't believe he reacted to the lights. It looked like Valtteri jumped."

FIA, motor sport's governing body, had the final word and ruled Bottas did nothing wrong.

"Simply put, he made an exceptionally accurate and fortuitous call, anticipating the moment the lights went out with great precision," FIA said in a statement. "It was within the tolerances allowed."

A chaotic start in midfield saw Alonso's car sent spinning. Stewards decided Kvyat caused the crash and he was given a drive-through penalty.

Alonso has completed only two races in a frustrating season - but at least this time the Honda engine on his McLaren was not to blame.

By lap 10 of 71, Hamilton was fifth behind Ferrari's Kimi Raikkonen and Ricciardo.

Up ahead, Bottas was eight seconds clear of Vettel on the picturesque 2.7-mile track.

Hamilton changed his tires on lap 32, while Ricciardo and Vettel made their changes soon after.

This shook up the order, with Bottas now leading from Finnish countryman Raikkonen - both yet to change their tires. Vettel was in third ahead of Ricciardo and Hamilton, who was complaining about a balance problem on the rear of his car.

Bottas finally came in on lap 41.

After what appeared a cumbersome tire change, he came out behind new leader Raikkonen, then overtook him again to regain control.

Ferrari then pitted Raikkonen, jumping Vettel up to second, about four seconds behind Bottas.

Vettel was working hard to close the gap on Bottas, while Hamilton was gaining time on Ricciardo and crossed the line only 1.4 seconds behind.

"I just stuck to my braking points and close to the limit," Ricciardo said.

"The second-last lap was the tightest."

The 10th race of an exciting season is the British GP at Silverstone next weekend.

Associated Press