Despite what appeared to be another comfortable run at the head of the F1 field in Malaysia, Sebastian Vettel insists that he had Red Bull's KERS system to thank for his second win of the 2011 season.

The German's comments come with a touch of irony after team-mate Mark Webber found that he could not use his system at all during the race, and Vettel himself had to stop using it in the latter stages of the 56-lap encounter - emphasising Red Bull's decision not to run KERS in Melbourne two weeks ago because of its unreliability.

While Vettel made a textbook getaway from pole position, he was aided in his quest for victory by Nick Heidfeld's extraordinary start, which saw the Lotus Renault driver sweep around the outside of both McLarens and both Ferraris to snatch second place from sixth on the grid. Indeed, such was Heidfeld's audacity, Vettel admitted that he had had to call on KERS to keep himself in front - a key move as Heidfeld's pace was enough to stymie Lewis Hamilton in the early stages and prevent the Briton from challenging his front row partner.

"I think it shows how important KERS is - it saved our life today at the start," Vettel claimed, "I was focused on Lewis behind me and, all of a sudden, Nick was there, so it was quite funny in a way. I had to defend a little bit into turn two, focus on a good exit, which was crucial as then I was ahead and could use the first stint to build up a little gap.

"I think we were a little bit quicker than the Renault [and] I tried to take that gap into each stint. It was a bit of a luxury situation as we could wait for other people to do their stops. Of course, they were closing then, as it is quite powerful - if you change tyres, you come out and you are much quicker than the guys out on the circuit with the used tyres. But, with a couple of seconds in hand, we had this luxury, so there was no need to panic.

"Without KERS, we would have been in a completely different position and the race would have unfolded in a different way. It was giving us what we needed. Coming here, only ten days overseas, reacting the way we did, we can be very proud of ourselves. We had a little problem - at some stage, [my engineer] told me not to use KERS - then we activated it again. I don't know what was the problem. Obviously, something was wrong."

Despite the loss of KERS, Vettel's pace remained consistent and, when under threat, the German was even able to raise his game a little to ensure that his lead was safe.

"Obviously, as I tried to explain before, I think it's very difficult to read the true pace," he said, "At some stage, in the third stint I think, so my last stint on options, I was lapping a second a lap quicker than Lewis for two or three laps. At that stage, I don't think I used KERS."

Despite the obvious problems with RBR's system, Vettel insisted that the team could not consider pressing ahead without it.

"I can assure you that not running KERS, for us, is a disadvantage," he stressed, "As I tried to explain, we worked very hard and we got it working but, in the race, something happened. I don't quite yet know what it was, but we used it for the majority [of the race]."

The German made three tyres stops during the race, in common with the majority of his rivals - only Webber, Hamilton, Fernando Alonso and the retired Tonio Liuzzi made four - but insisted that he had not suffered from problems with his Pirellis, despite Hamilton appearing to hack into his advantage.

"As Jenson [Button] said, you never knew how hard to push, how hard to save your tyres," he reflected, "Everyone was trying to do the same. I think there was a lot to learn today and a lot to take into the next race.

"[Hamilton] pitted earlier than Nick, and earlier than us, and I think he went to another set of options after his first stop. As I have just tried to explain, it is very powerful and I think we were stopping at the right time in the first stint. Wet tried to push probably a bit longer for the rain, whereas he came in and that one lap can make three to four seconds difference. Naturally, he caught up and then I was just trying to look after the tyres and look after the gap. He was closing in at three-tenths a lap at this stage, but we again tried to push that stint as far as we could, so I wasn't worried when he was catching up these couple of laps.

"Jenson described how he struggled on the first stint, but he was very happy in the last stint. Within one race, with a different set of tyres, there were some things that you can fine tune in the car. Potentially, that can make a big difference. The fact is that, if you feel comfortable in one stint compared to the other, it can make a difference in pace."