The Usual Suspects star offered an afternoon of his company to raise funds at the star-studded event, held in memory of former Russian President Mikhail Gorbachev's late wife Raisa, who died of leukaemia in 1999.
Stars including Anjelica Huston, Dougray Scott and Joely Richardson were among those invited to place bids at the gala at the British capital's Hampton Court Palace.
Diamonds, luxury holidays, artwork by Jeff Koons and a Francis Bacon triptych also went under the hammer, with proceeds going to the Marie Curie Cancer Care and the Raisa Gorbachev Foundation.
The Foundation's founder, Evgeny Lebedev, says, "Mikhail Gorbachev and I were so moved by the generosity of our guests who helped us to raise this astounding figure. This will go a long way to help lessen the suffering of so many children and their families - as was Raisa Gorbachev's aim."