Prost's battles with Ayrton Senna were particularly notable. The rivalry originated in 1988, when Senna joined Prost at the McLaren team. The most notable event during the season between the two occurred during the Portuguese Grand Prix, where Senna tried to block Prost from taking the lead by forcing him to run close to the pit wall at around . Prost managed to edge Senna outwards, taking the lead as they went into the first corner, but remained angered by Senna's manoeuvre.