Daniel Ricciardo says he made a "rookie error" deciding to stay in the pits during the final part of qualifying for the British Grand Prix.
Ricciardo's Red Bull team-mate Sebastian Vettel qualified second after completing a late run on dry tyres, while Ricciardo slipped from fourth to eighth after electing not to go out before the track improved in the closing stages.
The Canadian GP winner admitted he cost himself a better grid position by misreading the changing Silverstone conditions.
Ricciardo said: "I don't know what to say. I went on the scales thinking that was it and now I'm P8. Rookie error.
"I really thought the track wouldn't get quicker, especially as the rain kept dropping, and not only did it get quicker, it got a lot quicker.
"I thought we were OK. The last bit of the track in the first run was dry then it started raining quite heavily in the last sector.
"It was good enough for fourth, I saw the rain falling in the pitlane and I said "no way the track is going to get better" but it did.
"So I guess this track dries a lot quicker than some others.
"I don't think Seb expected to go quicker either, he just went to set a time
"I'm a bit gobsmacked how that got so much quicker in the last minute, but I've got to learn from that."