In 1973, the Ferrari 312B3 was no longer competitive, and Ickx only managed one fourth place at the opening Grand Prix of the season. While being successful with their sports cars, which were driven to several wins by Ickx himself, the Formula One programme of the Italians was outclassed, and they even had to skip some races, notably at the Nürburgring. This was not acceptable to Ickx, who left the team halfway through the season (after the 1973 British Grand Prix, where he finished eighth). Instead, he competed in the German Grand Prix at the Nürburgring in a McLaren, and scored a sterling third place behind the all-conquering Tyrrells of Stewart and François Cevert. Ickx returned to Ferrari for the Italian Grand Prix at Monza again finishing eighth but drove for Williams in the 1973 United States Grand Prix at Watkins Glen finishing seventh.