The fractious relationship between Senna and Prost didn’t take long to bubble over at the start of the 1989 season. Senna ran into an early lead in the championship, winning three out of the first four races. Prost felt Senna had gone back on a pre-race  agreement at the restart of the San Marino Grand Prix when he passed the Frenchman to take the lead and go on to win. His early season dominance was halted by a series of technical problems with his car. He failed to finish the races in the USA, Canada, France, Britain and Italy due to car failure plus collisions at the Brazilian and Portuguese races put Prost in the driving seat for the championship. As in 1988, the Suzuka circuit in Japan would see the title decided. With Senna needing a victory to keep his chances alive for the final round in Australia, he trailed Prost in the early stages of the race as the two pulled clear of the field. After both pitted for new tyres, Senna set about closing the gap on the race leader. By lap 40, he was just a second behind and looking much faster at this stage of the race. Senna shadowed Prost’s every move until on lap 46, he got a good run out of 130R and pulled alongside into the breaking zone for the chicane. Seeing Senna in his mirrors, Prost moved right towards Senna, the pair collided and with the cars locked together Prost jumped out of the car. Senna was gesticulating to the marshals to help him bump start his car after it was freed and managed to fire up the Honda engine down the slip road. Having to do a full lap with a damaged nose cone to get back to the pits, the Benetton of Alessandro Nannini roared into the lead as Senna made his way out of the pits. Senna had five laps to catch and pass Nannini, with the extra grip of the fresh rubber from the pit stop, he was quickly on the back of him and passed to retake the lead at the chicane where he and Prost had tangled. Senna crossed the line to take what looked like a victory to take the championship down to the wire. However, after a lengthy meeting with the stewards that saw the podium presentation delayed by half an hour. Senna was disqualified for missing out the chicane when he was bump started, meaning that Prost was controversially crowned Champion. A large fine and temporary suspension of his Super License followed in the winter of 1989 and an irate Senna engaged in a bitter war of words with the FIA and its then President Jean-Marie Balestre. Senna finished the season second with six wins and one second place.

A more harmonious atmosphere was found in the McLaren garage for the 1990  campaign with Gerhard Berger joining from Ferrari. The season got off to a spectacular start for Senna with a hard fought win in Phoenix, battling wheel to wheel with rookie Frenchman, Jean Alesi’s Tyrrell. By the midpoint of the season, Senna had five wins to his name with Prost again his closest rival for the title. As was the tradition between the two, the title was decided around the figure of eight, Suzuka track. Senna had taken pole for the race but was incensed when the stewards moved pole position to the dirty side of the grid, handing second placed Prost the clean side of the track. At the start of the race, Prost took full advantage of the extra grip on the racing line to edge into the lead. Senna was in his slipstream and dived for the inside as they turned into the first corner. Like the year before, the pair collided and both were instant retirements, handing the drivers title to Senna.

The defending champion got off to a flying start in 1991, winning the first four races to again build an early advantage. Williams, with their Renault engines looked like the team to worry Senna. After overcoming teething problems with their semi-automatic gearbox, by mid season Nigel Mansell’s run of three straight win had put him within striking distance of Senna. The Brazilian went into the penultimate round at Suzuka knowing that Mansell need to win the race to keep the championship alive. Senna made a good start, leading Mansell in the early stages. Mansell’s chase ended prematurely when his went wide in turn 1, spinning off into the gravel on lap 10. Senna went on to finish second to win his third title in four years, becoming the youngest triple world champion at 33 years of age.

In 1992, it was clear from the offset that the McLaren was no match for the Williams FW14B with its active suspension. Senna endured a frustrating year with only three wins coming his way. The pick of which came at Monaco. Senna trailed Mansell from the start after jumping Patrese into second. Mansell looked set for his sixth straight victory of the year until a loose wheel nut forced him to pit, giving the lead to Senna. With eight laps to go, Mansell cruised up the back of Senna’s car. With his tyres at the end of their life, Senna produced a masterclass in defensive driving to hold of Mansell for the last three laps to take another famous victory at Monaco. Senna finished the year in fourth place with 50 points.

Senna was in talks with Sir Frank about the possibility of driving for the team in 1993. Williams had signed Prost, who took a sabbatical year in ’92 after being fired by Ferrari. Prost stipulated in his contract that Senna could not be his team-mate, scuppering the chance of any deal. Despite Prost’s advantage in the superior Williams, Senna took two wins and a second in the first three races, including his famous victory in the European Grand Prix at Donington Park. Senna started fourth on the grid and dropped behind the Sauber of Karl Wendlinger before putting in what is widely regarded as his finest racing lap. He was quickly up to third into the Old Hairpin, passing Schumacher and Wendlinger and closing on the Williams of Hill. He passed Hill into Mclean’s to put him up to second before diving up the inside of Prost at the Melbourne Hairpin to take the lead. Senna went on to lap the entire field apart from Hill, who finished the best part of a minute and a half behind. Senna won five races in 1993, including his record breaking 6^th victory at Monaco, a record that still stands today. His final win of the year, and of his career, came at the season’s finale at Adelaide to finish runner up to Prost with 73 points.

With Prost retiring at the end of the year, Senna finally made his move from McLaren to Williams. With the banning of several driver aids, including active suspension. Williams no longer had the speed advantage that they’d enjoyed for the previous two years. Senna wasn’t happy with the balance of the car from the offset, which was compounded by the pace of Schumacher in the Benetton Ford. Senna failed to finish the first three races, spinning out of second at his home race in Brazil while lying in second. At the Pacific Grand Prix he was punted out at the first corner by Mika Hakkinen and collected by Nicola Larini’s Ferrari. With both races being won by Schumacher, Senna was 20 points behind after two races. The San Marino Grand Prix weekend got off to a terrible start when Rubens Barrichello left the circuit at high speed after hitting the curb at Variante Bassa, sustaining a broken nose and arm. Twenty minutes into qualifying, Austrian, Roland Ratzenberger became the first driver to lose his life in a race weekend for 12 years after hitting the wall at the fast Villeneuve Curva. The whole paddock was shocked by these events, Frank Williams was unsure if Senna would take to the grid for the race the following day.

On Sunday 1^st May, Senna took his position at the head of the grid for the start of the race, when the race got underway, the Benetton of JJ Lehto stalled and was hit by the Lotus of Pedro Lamy causing the safety car to be deployed. When the safety car returned to the pits, Senna led Schumacher, trying to build a gap. Two laps later, Senna’s car left the circuit at 190MPH at the Tamburello corner, hitting the concrete wall on the outside. The race was red flagged as medical personnel rushed to help the unconscious Senna. He was lifted from the wrecked Williams and airlifted to Maggiore Hospital in nearby Bologna. Medical teams continued to treat him during the flight. At 6.40 local time, the doctor who had worked on Senna announced the he had died from his injuries. He gave the time of death as 2.17 local time meaning he died instantly. The post mortem revealed that part of the cars suspension has pierced through his helmet and into his skull.

In the wake of Senna’s death, the Brazilian government declared three days of mourning. An estimated three million people lined the streets for the funeral, among them were  Alain Prost, Jackie Stewart, Damon Hill, Rubens Barrichello, Johnny Herbert, and Emerson Fittipaldi who were among the pallbearers. Ayrton Senna’s body was laid to rest at the Morumbi Cemetery in his home town of Sau Paulo.