Complex sentence: At the year-ending Tennis Masters Cup in Shanghai, Federer defeated defending champion David Nalbandian in one of his three round-robin matches and Rafael Nadal 6-4,7-5 in a thrilling semifinal match of the top 2 players in the world.
Split into simpler sentences: At the year-ending Tennis Masters Cup in Shanghai, Federer defeated defending champion David Nalbandian in one of his three round-robin matches. He also socred his second victory of the year over rival Rafael Nadal 6-4,7-5 in a thrilling semifinal matchup of the top 2 players in the world.