With only 10 laps to go , Siffert began to slow .
Fittipaldi in the Lotus was pulling out all the stops to catch him - and looked like doing so unless Siffert spurted .
With only 10 laps to go , Siffert began to slow and Fittipaldi in the Lotus was pulling out all the stops to catch him - and looked like doing so unless Siffert spurted .