On entering S?o Paulo TMA, the flight was cleared to descend to FL 50. However, as FL 60 was attained instructions were given to hold at that level because another flight on approach had initiated a missed approach. After the latter had succeeded its second approach, the flight was cleared to land. When decision height was reached the pilot held his altitude for a while until he was able to see the runway lighting. The descent was then resumed at a greater rate than normal and the aircraft touched down beyond the middle of the runway. Both normal and emergency brakes were applied but their effectiveness was impaired by the wet concrete. When it was apparent that the aircraft would not come to a stop within the runway limits, the pilot tried to make an abrupt turn. The aircraft went off the runway, collided with a concrete sentry box and went over an embankment.