Lewis Hamilton says he was baffled about the reasons for his poor start to the Indian Grand Prix.
The British driver had qualified in third position but came under attack from team-mate Jenson Button right after the start.
The duo were embroiled in a battle over the first corners, with Button emerging ahead and Ferrari's Fernando Alonso also passing Hamilton down the straight as a result.
Hamilton, who finished the race in fourth position, admitted even without a good start he would have been unable to challenge the cars in front.
"I don't yet understand why I got such a poor start - it lost me ground and then I fell under attack from the guys behind," said Hamilton.
"During the first lap, I was primarily focusing on not colliding with Jenson, then I saw Fernando [Alonso] in my right mirror. He was towing me from very far back.
"Even if I'd had a better start than I did, the guys in front were still maybe a bit too fast, particularly in the first stint.
"During that first stint I started having a downshift problem - I was having to change down with my right hand instead of my left, so the team elected to change the steering wheel at the pitstop."
The McLaren driver came close to beating Mark Webber to third place in the closing stages of the race, but in the end had to settle for fourth after running out of time.
"I tried to chase down Mark [Webber] in the closing laps, but by then it was too late and he was going too quickly for me to be able to mount a serious challenge," he said.
"But I never give up, and, right until the very last corner, I thought I might just be able to catch him, but in the end it wasn't to be.
"Still, I loved it out there today - I can't remember the last time I've pushed so far, so hard, for so long, right on the limit - it felt great.
"It felt fantastic, in fact, to be in the middle of such a battle."