Sebastian Vettel has admitted that he should perhaps have been more aggressive in the Canadian Grand Prix, despite making an error that allowed Jenson Button to snatch victory on the last lap.

The reigning world champion appeared to have a sixth win in seven races in the bag as he led from the start of the Montreal event, surviving worsening conditions and a two-hour red flag stoppage before opening out a comfortable lead in the 'second half' that initially appeared enough to carry him to the chequered flag. Button, however, had other ideas and, having scythed his way back from the back of the field after five tyre changes and a drive-thru' penalty, he closed remorselessly on Vettel until eventually the German felt compelled to respond.

Ironically, had the Red Bull driver lapped a little slower, the race may never have reached the fateful final lap as the conditions slowed lap times significantly for much of the duration, but Vettel was left chastising himself for not upping the pace in the wake of the final safety car following Nick Heidfeld's retirement.

"I should probably have pushed much harder initially after the safety car, after the restart," he lamented, "I was building up something like a four-second lead and then I thought that the people behind would run a similar pace, so I wasn't trying to pull away too much because I don't know what might happen afterwards with tyres or another safety car phase. I was probably a bit too cautious there.

"If I would have pulled away by six or seven seconds, then it would have been a different story but, at some stage, it was only three. It was a difficult finish to a hard race, and I could see that especially in the last sector, Jenson was coming very close and catching up a lot.

"There were no [tyre] issues - just, after the safety car, I probably wasn't aggressive enough because to me, initially, there was no need. As it turned out, I would have been much better off. After that, when I saw Jenson behind, I kept him fairly close and, yes, he was very quick, but it wasn't a second per lap any more. I think it was then within a couple of tenths. It would have been very close but, with the mistake I made, it was not."

In common with the rest of his season, however, Vettel escaped slightly, in that two of his on-form title rivals failed to score, with Lewis Hamilton and Fernando Alonso both going out following incidents with Button. The German now leads the Montreal winner by 60 points in the overall standings, with team-mate Mark Webber holding third place, a further seven points behind.

"Surely, I think it is a good day today and, all in all, I think I can be satisfied but, at the moment, the freshest impressions I have are the ones which I probably show at the moment," Vettel said as he reflected on a victory lost, "The safety car never helped us, but we did the best we could. It is good points today - I can see that. It is important to finish, especially in a race like that, but to lead the race all the way and do the mistake in the last lap - probably the only real mistake I did in the whole race - is not very sweet. In the end, I got away with second."