Australian Mark Webber bemoaned the 'demoralising' loss of his Kinetic Energy Regeneration System (KERS) on his Red Bull car on Sunday after struggling to hang on to third place in the Indian Grand Prix.
He was running in a comfortable second place in the early stages of the 60-laps race, but after about 20 laps he said he began to suffer from intermittent KERS problems that restricted his ability to defend his position, notably in battles on the straights.
He said: "I think it started to go wrong around lap 19 or 20, maybe a bit earlier.
"It was on and off, and then completely off. It was a moving target. We needed to screw around with brake balance, and just manage as best we could.
"We needed to keep the focus, but it is so demoralising on that straight with no KERS - it is not really a battle at all."
In the closing stages, he was left vulnerable to Fernando Alonso of Ferrari, who made several attacks before cruising past him on the back straight.
Lewis Hamilton of McLaren then moved within attacking distance, but Webber was just able to hang on in the final three laps.
He finished third just seven-tenths of a second ahead of Hamilton who may well have passed him if there had been a further lap in the race.
Webber also complained about the behaviour of drivers at the back of the field.
He said: "The blue flags did nothing for back-markers, the guys don't know how much they kill us in the corners. And when I had no KERS, Fernando came past - they have good top gear - and that was it.
"I pushed as strong as possible to get to the end of the race, but I was lucky Lewis made a mistake on lap 57. That was important because he was starting to get a bit of momentum. I was keen to keep him out of DRS as much as possible.
"I am pretty happy with how I drove, but not enough - I think I could have got more points today for sure..."