Complex sentence: Massa's victory in the race enabled him to overtake his team-mate, Räikkönen, in the Drivers' Championship, moving him into second, and was Hamilton's closest rival, behind by six points.
Split into simpler sentences: Massa's victory in the race enabled him to overtake his team-mate, Räikkönen, in the Drivers' Championship, moving him into second. He was now Hamilton's closest rival, behind by six points.