Valtteri Bottas beat Mercedes team-mate Lewis Hamilton to pole position with his last lap of qualifying at the Emilia Romagna Grand Prix.
The Finn was 0.097 seconds quicker than Hamilton, with Red Bull’s Max Verstappen third nearly 0.5secs behind.
Alpha Tauri’s Pierre Gasly was a surprise fourth, ahead of Renault’s Daniel Ricciardo and Red Bull’s Alexander Albon.
On Sunday Mercedes could win a seventh consecutive constructors’ title.
They will do so as long as Red Bull do not out-score them by 34 points.
On F1’s first two-day weekend, returning to the Imola track that has not hosted a race since the 2006 San Marino Grand Prix, Hamilton was quickest in the single practice session on Saturday morning and was again on top after the first runs in final qualifying.
But a messy lap by Hamilton on the final runs gave Bottas a chance and he grabbed it with both hands.
“I really enjoyed it, this track,” Bottas said. “When you push flat out, it’s beautiful. I knew I had to push in the last lap and it’s a great feeling when you get those.”
Hamilton said: “Valtteri did a great job and it was a poor lap from myself. These things happen. You can’t get it right all the time.
“What a beautiful place we’re in here in Italy and the speeds we’re going around this track are unbelievable.
“I am pretty certain we’re going to see a boring race tomorrow. You can overtake into turn one but it is pretty narrow and you can’t overtake on the rest.”
The stand-out performance of qualifying came from Gasly, who was confirmed as an Alpha Tauri driver for 2021 earlier in the week, as the team made a step forward and he lapped just 0.326secs slower than Verstappen in the Red Bull.
His result will pile further pressure on Albon, who is under threat of losing his Red Bull drive at the end of the season.
Red Bull have made it clear Albon needs a good race this weekend as they assess whether to keep him on or replace him with an experienced hand such as Nico Hulkenberg or Sergio Perez.
Albon was 0.396secs slower than Verstappen.
Ferrari will be disappointed with seventh place on the grid for Charles Leclerc, but the 23-year-old was again superior to team-mate Sebastian Vettel, who continues to struggle with the car and could manage only 14th on the grid.
Alpha Tauri’s Daniil Kvyat and the McLarens of Lando Norris and Carlos Sainz completed the top 10.
And George Russell was again outstanding in the Williams, taking 13th place.