Lewis Hamilton believes he would have managed pole for Saturday's United States Grand Prix sprint race had he not been disrupted by yellow flags.
Hamilton was heard to question Mercedes' decision to put him and George Russell on track so soon into SQ3, although Russell demonstrated the team's rationale by putting together a time good enough for second on the grid.
Behind him, Hamilton had found a significant margin over Russell's opening sector and was looking set to outqualify his team-mate - but he encountered a yellow flag in the second sector when Franco Colapinto spun at Turn 12.
GPS data shows that Hamilton lifted much earlier on compared to Russell into that corner, which the seven-time champion encountered moments before the yellow flag was removed, creating a swing of almost eight-tenths as Hamilton was tracking at three-tenths ahead of Russell - though the former had also run wide when trying to make up for the lift.
Asked if he felt that it was a lost sprint pole, Hamilton replied: "I just got unlucky with the yellow flag. And that's what it is. I was four-tenths up, but anyhow, it is what it is.
"The good thing is the team has made a step with the car, the upgrade has clearly worked and I'm really grateful to everyone back at the factory for all the hard work over this period of time.
"It's been a tough slog for everyone to get the upgrade and to make sure that they're working. It's not the end of the day. Tomorrow we get another chance."
Both Mercedes drivers suffered spins in free practice as the W15 looked difficult to drive on the bumpy Circuit of the Americas track, but a clear improvement was evident during sprint qualifying.
"We did a great job in between [the sessions] to make changes to the car," Hamilton added.
"It's always a bit of a gamble because you don't know whether or not it's going to work, the changes that you make, but you hope they do what you aim to do with them.
"As soon as I got into the car, it was like night and day different. So it was great work from the guys in the garage and with Bono [race engineer Pete Bonnington] and Mike [performance engineer Michael Sansoni] - it was a great job."
