Complex sentence: After this performance, he started the hot favourite for the Irish Derby and won by four lengths despite the presence of a large abscess in the saddle area and the need to have foam pads under the saddle to enable him to run.
Split into simpler sentences: After this performance he started the hot favourite for the Irish Derby and duly won by four lengths. This was particularly impressive as he had a large abscess in the saddle area, having to have foam pads under the saddle to enable him to run.