Complex sentence: He finished the marathon in a new world record time of 2:12:11.2; 4 minutes, 8 seconds in front of the silver medalist Basil Heatley of Great Britain who overtook Tsuburaya inside the stadium.
Split into simpler sentences: He finished the marathon in a new world record time of 2:12:11.2. That was four minutes and eight seconds in front of the silver medalist Basil Heatley of Great Britain who overtook Tsuburaya inside the stadium.