At first, Stewart was able to open a gap back to the following group, now headed by his teammate, but after ten laps, his tires began to go off and the gap closed. The Scot realized that Cevert's Goodyears were holding up much better in the heat, and when Cevert closed up right behind him, he waved him by on lap 14. Hulme was now struggling with a terrible vibration in his tires and was passed, first by Ickx, then Regazzoni and Siffert. On lap 15, American Sam Posey, in his first Grand Prix, retired from a fine run with a blown piston in his Surtees. By the time Ickx could get around Stewart on lap 17, Cevert's lead was 5.7 seconds.