On this day in 1991, Ayrton Senna clinched his 27th F1 victory, winning the US Grand Prix in Phoenix. The Brazilian had taken a very late delivery of his McLaren-Honda MP4/6, but the lack of testing was no hindrance for Senna who outraced Ferrari's Alain Prost and Williams boys Nigel Mansell and Riccardo Patrese on the concrete street circuit.
