Formula 1 - 1989 - Round 04 - Mexico GP

Senna chose medium compound Goodyear "B" tyres for the race while Prost went for the softer C-compound tyres in the hopes of gaining a speed advantage. Despite the pole being on the dirty side of the track in Mexico, Senna made a better start and was able to lead into the first turn from Mansell, Prost, Berger, Patrese and the Tyrrell-Ford of Michele Alboreto. However, it all meant nothing as Modena spun his Brabham into the Peraltada on the first lap and was tapped by the Ligier of Olivier Grouillard and finished against the tyre wall. Despite the car not being in a dangerous position, the red flag was shown and the race had to be restarted.

Senna won the restart and led Prost, a fast starting Berger, Mansell and the Williams pair of Patrese and Thierry Boutsen. Prost, with his softer tyres giving him better grip, soon moved onto the back of his teammate's car. However, Mexico would be where Prost started questioning the power of his Honda V10 compared to the ones used by Senna. For a number of laps Prost, clearly faster through the final Peraltada curve coming onto the main straight, could not make an impression on Senna despite being in his aerodynamic tow on the 1.2 km long main straight. Indeed, the #1 McLaren was seen to pull away from the #2 car on the straight. Running close to his teammate eventually had a detrimental effect on Prost's tyres and he was soon into the pits for a change of rubber. The McLaren team then mistakenly gave the Frenchman another set of C tyres rather than the B's he had come in for. Prost was soon back in for another tyre change and went back into the race only seconds in front of Senna who now had nearly a lap lead over his closest championship rival. Despite being on far fresher tyres than his teammate, Prost still lost ground to Senna and was eventually lapped when the Brazilian swept past on the main straight, fuelling Prost's claims that his engines were down on power compared to Senna's. McLaren team boss Ron Dennis later publicly apologised to Prost for the error in his pit stop.

Both Ferraris ran well until Berger's race ended on lap 16 with transmission failure while Mansell's gearbox lasted until lap 43. This left the Williams of Patrese in second place with Alboreto a surprising third. This was how the top three finished with Alessandro Nannini fourth in his Benetton B188. The Benetton team had hoped to have their new B189 available in Mexico, but ongoing problems with the new Ford HB engine meant the team had to continue using their 1988 car and engines. Prost, having unlapped himself, finished fifth to be the last car on the lead lap, while Italian Gabriele Tarquini scored the final point for sixth in his AGS-Ford, which proved to be his only point in Formula One.