The player, now with Glasgow Celtic, was fined on two charges of common assault and ordered to pay costs of £200 with £200 compensation to Richard Partridge, 25.
Horseferry Road magistrates' court, central London, was told that Sutton and nine friends went to a Soho restaurant to celebrate his wife's birthday last October. As they left at 3am Sutton, 27, of Sarratt, Herts, bumped into Helen McNamara, 23. Mr Partridge was with Ms McNamara. It was alleged that someone called out to the football party that one was a "third-string player".
Mr Partridge said that Sutton became abusive: "This went on for no more than 30 seconds. Then he spat at my face. He spat dead centre on my face, my nose."
He had not wanted to provoke anything because Sutton was a foot taller. Mr Partridge said: "I began to walk away and the next thing I knew Chris Sutton started walking towards me. He came up to me and said, 'If you have got something to say to me, say it to my face,' and he spat at me in the face again."
Sutton told the court that he had drunk two glasses of wine. He said: "As I left to come down the steps I stumbled into a lady and apologised on more than one occasion. The lady didn't seem happy with an apology. I then continued to walk down the steps and there were some words from a group."
Lewis Power, defending, said: "There is always someone looking to take a pot shot at someone famous."