Leading the race on the 15th lap of the Chinese Grand Prix, McLaren's Jenson Button decided to make a routine pit stop.
It turned out to be not so routine when he discovered that the pit belonged to Red Bull.
He was brusquely dispatched towards his own pit one place ahead but the damage was done.
Sebastian Vettel, who arrived on Button's heels, was momentarily kept waiting but recovered quickly to exit in front of his mortified rival.
It was a costly gaffe by Button who eventually failed to finish on the podium.
Image: McLaren-Mercedes driver Jenson Button of Britain (R) is followed by Red Bull-Renault driver Sebastian Vettel of Germany during the Formula One Chinese Grand Prix in Shanghai on April 17, 2011.