You need to beat Alberto Ascari's record, so it's 10 successive victories. Whilst 10 successive victories may sound daunting, the fact that you can do it on any difficulty means it's actually very easy. In career mode, choose easy and set the distance to 3 laps. Do a lap or two in qualifying so that you're near the front of the pack for the race. Once you are in front, you shouldn't be caught. If you have an accident, use the flashback feature () to rewind. As soon as you win your 10th consecutive race, the achievement will unlock.