Lewis Hamilton said pitting too early in the opening stages of the Malaysian Grand Prix put him at a disadvantage for the rest of the afternoon.
The McLaren driver was up to second for a while and was closing on leader Sebastian Vettel. But Hamilton struggled to keep his tyres alive through what should have been an 18-lap final stint, and ended up dropping back to seventh after having to make an additional stop.
"I think through the race my tyres went off," he said. "We pitted too early, then we had to pit earlier, all the time we were pitting before everyone and my tires were just finished at the end.
"It's one of those days and you have to take it on the chin and move on."
Hamilton admitted that finishing seventh (actually eighth, after his post-race penalty) was a hugely disappointing result after pushing Vettel hard for much of the weekend and starting from the front row.
"This is racing, I guess," he said. "I started second and did everything I could to keep up, and I don't really have much to say."