The Mexican got through Q1 in fifth place and was fourth in Q2 before earning fifth spot in the final session, having struggled throughout to match the pace of team-mate Max Verstappen.
As the second occurrence of Pirelli’s alternative tyre allocation, with fewer sets and compulsory use of hard, medium and softs across the three qualifying segments, Monza was difficult for all drivers.
However, Perez made his own life difficult with a spin into the Parabolica tyre wall that saw him miss some crucial laps at the end of FP2.
It also had a knock-on effect into FP3, when he ran limited laps. After an oil leak curtailed his session, he had to undergo a power unit change, with the team putting in a previously used example for qualifying.
Asked if he was happy to have salvaged fifth place, Perez insisted: "Yes, considering the situation, missing FP3, basically going blind, I didn't run new tyres today before qualifying, and it wasn't an ideal day,” he said. “But it is what it is.
“I think given how small the margins were, our preparation was not ideal. We had a lot of pace yesterday, I think yesterday was looking great. But unfortunately, we didn't get to show what we were able to do today."
Source: Autosport