Phil Hill's win in the Italian Grand Prix at Monza on this day in 1961 delivered the world title to the American driver and to Ferrari.
It was a tragic coronation however, with Hill's team mate and title rival Wolfgang von Trips killed on the second lap of the race, along with 14 spectators.
The German driver's Ferrari had collided with Jimmy Clark's Lotus on the approach to Parabolica, careered towards the embankment and plunged into the crowd.
The Californian became America's first world champion, but there was no joy to be felt when the title was bestowed upon him.
Hill once recalled the aftermath of the tragedy.
"When they told me the news that Trips was dead, and more than a dozen spectators with him, I was stunned, deeply shocked.
"The papers reported that I broke down in tears and sobbed, but that was not true. When you've lived as close to death and danger as long as I have, then your emotional defenses are equal to almost nothing."