4: Legendary battle with Nigel Mansell at Monaco GP 1992
Graham Hill had always been regarded as the Master of Monaco, winning in the principality five times, a record which seemed insurmountable at the time. Senna had won four of the five previous iterations of the Monte Carlo race and was in a position to match Hill by the time 1992 rolled around.
Williams had different ideas, though, with Nigel Mansell having won all 5 of the previous rounds so far that season, and seeming as though he was already champion-elect. Mansell claimed pole position, the first time Senna hadn't started from 1st since 1987, and the Brit led into the first corner.
Red 5 pulled out a lead and seemed to head for victory, but a loose wheel nut curtailed his Grand Prix, even though he later rejoined. Senna inherited the lead, but Mansell, on new tyres and driving a superior Williams, closed the gap at almost 5 seconds a lap.
Mansell was on the gearbox of Senna's McLaren, but despite an impressive attack, Ayrton put up a legendary defence and held the Williams off for the win, matching the late-great Graham Hill. The next year, he's surpassed Hill, his final victory around the streets of Monte Carlo.