Jamie Casement, 22, punched Peter McLaren senseless during an unprovoked attack at Wemyss Bay railway station, on January 21.
As Mr McLaren lay motionless, Casement stamped on his jaw, shattering it.
The attack was captured on CCTV footage.
Sentencing Casement, judge Lord Bannatyne told him: "This was an entirely unprovoked attack on a wholly innocent victim."
He ordered Casement, whose address was given as Low Moss Prison, Bishopbriggs, to be monitored in the community for five years after his release from jail.
Casement admitted punching and stamping on Mr McLaren's head in the station concourse.
He has two previous convictions for violence.