Mercedes changed the face of the formula book when Valtteri Bottas led Lewis Hamilton in qualifying at Mexico City Grand Prix to score a one-two.
Max Verstappen, the championship leader, was unable to finish third, despite having dominated the weekend up until qualifying.
Hamilton leads Verstappen by 12 points going into the race. This is the first of five races in six weeks that will decide the title.
Hamilton has a great opportunity to make up some ground in the championship race if Hamilton is able to lock out Mercedes' front row.
Mercedes had expected to be behind Red Bull in pace when they arrived at the weekend. However, their performance as world champions was quite a surprise.
Mercedes took the win instead, as Red Bull looked strong during the practice sessions.
Hamilton stated, "We have been working very hard. We didn't think that we could keep up the pace this weekend, so it was quite special to secure the front row.
"I don't know what happened. They were ahead by 0.6 seconds at one stage, and then they were ahead by 0.4 seconds at another stage. But whatever happened in qualifying we had a better pace. "I'm as shocked as everyone."
Stroll fell in the first session
It was a gripping session
After a delay of nearly half an hour due to an early crash for Aston Martin’s Lance Stroll the first session of qualifying began as planned. Verstappen was well ahead of the Mercedes drivers by more than half a second.
The picture started to change when you got to the second part.
Because teams prefer to race on medium tyres over softs, Mercedes suddenly became competitive. Verstappen was just 0.16secs behind Hamilton.
It was not what many would have expected, but the Mercedes stayed there even when the teams switched to soft tyres in the final shoot-out.
Bottas was 0.35secs faster than Verstappen in the initial lap, Hamilton being between them.
Verstappen complained about his rear grip but was hopeful that he would improve enough to challenge for pole on the second and final lap. However, his chances of winning pole were ended when Yuki Tsunoda from Alpha Tauri ran off in front Sergio Perez, Verstappen’s teammate.
Verstappen ran behind them, expecting yellow flag to come. His chances of getting a pole that looked certain for the entire weekend were gone.
Bottas stated: "It was an amazing lap, especially my lap 1 lap in Q3. It was a great lap and a great feeling.
Finn acknowledged that he was "definitely surprised" by his experience. We seemed off Red Bull, but managed to set up the setup perfectly.
Hamilton congratulated Bottas for an "awesome job", and Bottas, a seven-time champion, said that he couldn't have matched Bottas' time.
Hamilton stated that "We have been generally behind by half an second." Hamilton said that while we had been hard at work on the car, they have generally gotten higher downforce. This has caused us to struggle in some parts and it is a surprise to be on the front row.
Verstappen stated that it was difficult to get the tyres to fit properly. It was horrible the first time. It was clear that there was more if we did it right. It was possible to beat Valtteri’s time.
"It's not a great finish to a weekend of intense competition, but it's a long race to Turn One, so let’s see.
"We were really slow and had poor grip in Q3. We did manage to recover it on the final lap, but it is still not as fast as we would have liked.
"Tomorrow, we will race on different tires and I expect the balance of the races to be good again." "We just had terrible qualifying."
Why don't we do this often? There are many Verstappen fanatics all over the globe, but in Mexico they were outnumbered by Perez fans.
There are many penalties
Three Red Bulls are directly behind the Mercedes. Verstappen's colleague Sergio Perez is fourth, and Pierre Gasly's Alpha Tauri is fifth.
Carlos Sainz, Ferrari, was sixth ahead of McLaren’s Daniel Ricciardo. Yuki Tsunoda, Alpha Tauri's Yuki Takuda, was the second Ferrari of Charles Leclerc.
Lando Norris qualified for the final part of qualifying to give Ricciardo a slipstream. Briton was one of four drivers who were demoted to the back grid for exceeding engine allowances. Tsunoda and Stroll were the other drivers who qualified 15th.
Williams' George Russell will start in 16th place, despite qualifying 13th. He has a penalty for changing the gearbox.
