McLaren boss Ron Dennis has apologised to Kimi Raikkonen after mechanical failure cost him a possible victory in the San Marino Grand Prix.
"Kimi was doing a fantastic job and had pulled out a healthy lead over Fernando Alonso," said Dennis.
"Then a joint failed in the driveshaft, so apologies again to Kimi."
Raikkonen had earlier secured McLaren's first pole since the British Grand Prix of last July and looked a good bet for McLaren's first win of the 2005.
"Obviously I am disappointed as I had a great start and was really building on my lead," said the Finn, who threw his steering wheel across the team garage in disgust when he stepped out of the car.
"At least we know that the car has the pace in both qualifying as well as the race.
"With some improvements due for Spain in two weeks I am looking forward to a good race there."
Raikkonen's misfortune was McLaren's first race retirement of the year. The team are third in the constructors' standings with 24 points.
Austrian Alexander Wurz, standing in for McLaren's injured Colombian Juan Pablo Montoya, finished fourth in Italy.