Nico Rosberg admitted he "completely messed up" the start of the Belgian Grand Prix after he lost several positions from second on the grid.
In the first race since the driver aids clampdown was introduced - which meant manual starts at Spa - Rosberg dropped to sixth position after a very poor getaway.
From there, the Mercedes driver managed to recover to second in the end, but his chances of challenging Lewis Hamilton for victory had already been compromised.
The German admitted he needed more practice.
"I just completely messed up the start, which was annoying," said Rosberg, now 28 points behind Hamilton, who took his sixth win of the season.
"Mostly also because we did another formation lap so that puts more temperature and everything and things change.
"Eventually it is my job to do it well and I didn't do the job. I need to practice that a bit more, I think."
He added: "I fought my way through, I have to give it everything, on the edge all the way through.
"The car was awesome, it is great to drive. Lewis did a great job so it was not enough."