Jenson Button believes the mechanical failure on his McLaren MP4-31 cost him "big points" in the Bahrain Grand Prix.
The Briton was running ninth on lap 7 when a sudden loss of power in the car forced him to pull over on the side of the track - and he believes that subsequent attrition would have taken him a few spots higher up the order.
"I think today we had a chance of scoring some big points - and it's been a little while since we've been able to do that - but today wasn't the day," Button said.
"It's a tough pill to swallow - the pace was good, just cruising in ninth place behind the two cars in front, saving fuel, saving tyres, getting ready to pounce at the right time - but the right time didn't come.
"The people that I was racing [Romain Grosjean and Max Verstappen], they are in fifth and sixth.
"I think we had very good pace today. My long runs over the weekend have been very good. I feel that I could've put the car in fifth, sixth place."
Progress made but team needs to capitalise
Button was upbeat about the improved pace of the McLaren, but insisted that the team still needed to confirm it with results.
"I think we've got to take the positives away from this weekend," he said.
"My pace in FP2, Q1 was great, we were very close to Q3. It didn't work out in Q2, we had a problem, we actually know what the problem was now, with the tyres overheating before I started the lap.
"And we had a great start and it was looking like a great race and it's not really going our way.
"But there are many positives with the team and the car right now, just hopefully we can show it.
"The thing is with this race, there were so many retirements, incidents, that you've got to capitalise on - and we weren't able to do that."