Lewis Hamilton reckons his efforts in qualifying for the Belgian GP were undone by a decision to return to McLaren's "old" rear wing.
Having lost most of Friday's three hours of track-time due to the pouring rain, the day started with a bumper practice session as the teams and drivers worked on set-up ahead of qualifying.
It was during that hour-long session that Hamilton decided against running McLaren's new rear wing, opting instead to strap the old one back on his MP4-27 ahead of qualifying.
That decision, though, didn't pan out as the 2008 Champ had hoped as he finished down in eighth place, 0.821s behind his team-mate and pole-sitter Jenson Button.
"It has not been a great qualifying session for me," said Hamilton, who will line-up seventh on the grid due to Mark Webber's penalty.
"We opted to use an old wing this weekend. After P3, the new one wasn't feeling so great. We went to the old wing and it was an awful lot slower.
"I'll just have to do the best I can.
"Well done to Jenson, it was a great start for the second part of the season for him. I will try and do as best I can to back Jenson up tomorrow."
The Brit also voiced his displeasure over the wing decision on Twitter, revealing that it was four-tenths of a second slower than his team-mate's wing down the main straight.
"Jenson has the new rear wing on, I have the old," he Tweeted. "We voted to change, didn't work out. I lose 0.4 tenths just on the straight."