Complex sentence: At the first round at Brands Hatch, Jackson started at the pole position and led for over 3/4 of the race until rain started to fall and he lost grip in his RWD BMW.
Split into simpler sentences: At the first round at Brands Hatch, Jackson got himself on pole position. He then led the race until over 3/4 distance, before rain started to fall and Jackson lost grip in his RWD BMW.