Lando Norris looked set to secure his first ever top-three in Saturday's qualifying shootout at Imola until the McLaren driver fell afoul of F1's track limit rules.
Norris clocked in second fastest at the end of his final run in Q3, just narrowly behind poleman Lewis Hamilton. But the McLaren driver was almost immediately demoted down to a disappointing P7 for running wide at the chicane.
Had his 1m14.454s lap been deemed legitimate, Norris would have started Sunday's race P3, right between the two Red Bull's of Sergio Perez and Max Verstappen.
"Pretty disappointed, pretty annoyed with myself," said a frustrated Norris. "It was a very good day until then.
"I think the team did an awesome job, the car really came alive in qualie, we made a lot of improvements since Friday but that one lap I don't need to make a mistake on, I 'effed' it all up."
Norris sought no excuses for his mistake, insisting that track limit rules are "the same for everyone".
"At the end of the day it's my mistake and I've messed it up. From the outside it's a lot easier to just stay within the lines than when it is inside…
"When you're in qualie, and you're in Q3, and you have an opportunity to be P2-P3 or score your best result in qualifying, you're pushing. And when you're going at such a speed into such a high-speed corner, misjudging about this amount…is… [frustrating]."
Despite his botched flyer, Norris highlighted the step forward achieved by McLaren and his crews since Bahrain.
"I'm really happy, not with the job I've done, but with the team," he said. "We didn't start the weekend off well at all, we struggled in the beginning, but we made a lot of improvements.
"I think we understood a little bit more how the car works and how it comes alive, and a better operating window, and that's one of the things we had to learn from Bahrain where we struggled, and we changed it this weekend and we've done a better job."