World number one chess player Garry Kasparov has drawn with a computer in the first of a four-game match.
Kasparov is considered one of the greatest-ever chess players
Mr Kasparov and the computer's handlers agreed on a draw on the 37th move after three hours and 20 minutes of play.
In the Man v Machine series, Mr Kasparov has to wear virtual reality glasses, and call out his moves, which are posted on a virtual board.
Mr Kasparov has played computers before, beating an IBM computer in 1996 but losing a rematch a year later.
He admitted after Monday's game that he had had "some psychological
problems with this technology."
The 40-year-old grandmaster said: "The position was not easy technically. I think I missed a chance to consolidate my position."
Mr Kasparov, who played with the white pieces, won a powerful rook in exchange for a bishop, but was unable to check the computer programme's king.
The games are being held in New York, with the second game scheduled for Thursday. The final two games are on 16 and 18 November.
The computer program is called the X3D Fritz.
Because it was a draw, both sides gained half a point each.
If Mr Kasparov wins the match he will get $200,000, with $175,000 for a draw. If he loses, he will earn $150,000.
In 1996, Mr Kasparov beat the Deep Blue IBM computer, but lost to the machine a year later after the programme had been upgraded.
Earlier this year a series of six games with the Israeli Deep Junior chess program ended in a draw.