Valtteri was the star of the show in Austrian Grand Prix Qualifying, securing his second F1 pole with the fastest-ever lap of the Spielberg Circuit.
Valtteri: What a special feeling
The Finn beat Ferrari's Sebastian Vettel in a close-fought battle for pole, with the pair separated by just a tenth of a second.
After scoring his first F1 podium here in Spielberg in 2014, Valtteri claimed pole number two - the team's seventh pole in nine races and third in Austria in four years.
"What a special feeling," said Valtteri. "It's only the second pole for me and hopefully there's more to come.
"It was a good lap in Q3, if not quite perfect. Today was all about building up the confidence in the car. I got it set up nicely and it's great to get the second pole position of my career.
"I'm going to focus on my own race, rather than looking behind me tomorrow, but we will not underestimate the Ferraris. It's going to be close and should be an interesting fight. Hopefully Lewis can fight back and we can score strong points for the team.
"The weather could be important tomorrow but starting first, I won't complain if the rain stays away. The car feels great, especially on high fuel, and I'm ready to win. That's the only target. It's been too long since Russia."
Lewis: It's been a frustrating day for me
Lewis was third quickest, but will provisionally start Sunday's Austrian Grand Prix from eighth after taking a five-place grid drop owing to an unscheduled gearbox change.
"It's been a frustrating day for me," said Lewis. "I had a chance to be fastest today and I didn't quite put it all together on that final lap in Q3. I'm disappointed with my performance in Q3: it would have been great to do a better lap but it obviously wasn't meant to be. Valtteri did a fantastic job though to take pole.
"The gearbox issue hasn't played on my mind during the weekend but after qualifying you realise you're starting further back. I think it will be tough to make progress tomorrow. The pack is a lot closer than in 2014 when I fought up to P2. But perhaps the weather can come into play.
"I'll work as hard as I can to recover and try get as many points as possible. We still have great pace and the car has been fantastic here, so I know I've got the car to do the job. Let's see how it all plays out tomorrow."
Toto: Mixed emotions after qualifying today
Silver Arrows team boss Toto Wolff is expecting an exciting race tomorrow, with Lewis looking to make progress through the field and Valtteri out front and in control.
"Mixed emotions after qualifying today," said Toto. "Valtteri did the perfect job this afternoon - he built up his performance through the session and his second pole position is a good reward. He has lost out on positions by tiny margins this year, so it's great to see him claim pole by a few hundredths this time round.
"As for Lewis, we knew he had a bit of a mountain to climb with the grid penalty for the gearbox change. His pace in Q2 on the super soft tyre showed that he is in good shape for tomorrow - but unfortunately he lost some time in Turn 1 on his final lap and that meant he finished the session P3.
"But he will start the race on the super soft tyre, so he has options for the race. I think all the pieces are in place for a really exciting Grand Prix, with a chance that the weather could mix things up as well."
James: It will surely be an interesting Grand Prix
While Technical Director James Allison admitted that the team had hoped for a little more from qualifying, he remains positive and is expecting a top Grand Prix on Sunday.
"If I am completely honest, we had hoped for a little more this afternoon, but it seems churlish to be anything other than delighted by a splendid pole position for Valtteri and third place for Lewis, whose performance in Q2 showed that he has plenty of race pace to unleash tomorrow," said James.
"It will surely be an interesting Grand Prix, dodging the possible rain showers and making the most of our potential at this deceptively tricky track."