Yes. As Bull already stated. There are three things you are dealing with on lap one of the race that you don't during qualifying:
1) Full fuel load, aka heavier car.
2) Cold tires.
3) Slip stream from other cars, specifically as soon as the race starts as all the cars are close and in-line.
Thus, if you brake at the 150 mark in quali, you will definitely need to brake sooner on lap one.
Think the first chicane at Monza. What I like to do is, say the braking point is at the 150, when I see the 200 I left off the gas, then shortly thereafter start applying the brake at 90%. While the people in front are waiting until the last second and use 100% of their brakes, I make a gap then use 90% giving me 10% more should I need it. Awesome part is, I end up right back on their tails by the time we reach the turn. Only issue with this is you have to trust the people behind you, which is hard to do sometimes. This is a pretty common tactic though so if you're in a more experienced lobby then others will be doing the same thing.