Marshall had appealed the original NFL suspension and learned Thursday of the reduction.
He also forfeits his pay for an additional game, for a two-game total of $52,352.
NFL Commissioner Roger Goodell suspended Marshall for violating the NFL personal conduct policy with a series of misdeeds. At the time, Marshall was told the suspension could be cut to two games if he stayed out of trouble and kept in touch with a league-appointed counselor.
Goodell reduced the penalty after Marshall went to New York last week to appeal.
Marshall caught 102 passes for 1,325 yards and 7 touchdowns last season and has shown no falloff this summer despite suffering a gash on his right arm that required emergency surgery this spring and sidelined him for almost all of the team's offseason field work.
Copyright 2008 by The Associated Press