The McLaren MP4/8A driven by Ayrton Senna to his final Monaco Grand Prix win in the 1993 Formula 1 season is to be auctioned by Bonhams in May.
Senna finished 1993 - his final year with McLaren - second in the points and 16 behind eventual champion Alain Prost.
With this car, chassis number six, he claimed his sixth and last victory in Monaco – a record which still stands 25 years on.
Senna also drove the car in a further seven races that year, finishing second behind Prost on its debut at the fifth round at the Spanish Grand Prix.
Following its final race at the Italian Grand Prix, where Senna retired after contact with Damon Hill and then Martin Brundle, chassis six was used as a spare car for the final two rounds in Japan and Australia, both of which Senna won.
The Ford-powered MP4/8A is listed by Bonhams as being "startlingly well-preserved" and in "running order".
Although Bonhams will not quote an exact estimate, it expects the McLaren to fetch a high seven-figure sum when it goes up for auction on May 11 at the Monaco Sale.
In November last year Michael Schumacher's final Monaco Grand Prix-winning 2001 Ferrari sold for $7.5million, making it the most valuable modern era Formula 1 car ever sold at auction.
Mark Osborne, Bonhams' specialist global head of motorsport, said: "Ayrton Senna was the most charismatic grand prix car driver of the modern era, and the MP4/8A was the car with which his team, McLaren, surpassed Ferrari as the most successful team in Formula 1 world championship history.
"This particular chassis, number six, cemented Senna's legend as The Master of Monaco. We at Bonhams are both honoured and thrilled to be presenting one of the most significant grand prix cars of all time."