Willie Parker (75 yards)
Tony Dorsett. Dorsett had a 99 yard run from scrimmage against the Minnesota Vikings on January 3, 1983.
Joseph Adahai had a 26 yard run
Well if your only talking about a run play from scrimmage, Fred Taylor's 90-yard touchdown run in January 2000 vs. Miami is the longest run play in NFL playoff history! The second longest being Ray Rice's 83-yard touchdown run on the first snap from scrimmage against the New England Patriots
Walter Payton's longest rush from scrimmage was 76 yards against the Denver Broncos on October 16, 1978.
Isaac Redman of Bowie State University set the record for the longest run from scrimmage (99 yards) versus Morgan State University in 2005.