Hambrick is best known for being the player that replaced Smith as the Cowboys starter in the 2003 season. As the featured running back, using his size and deceptive speed, he rushed for career highs with 275 carries for 972 yards and 5 touchdowns, helping the team back to the playoffs for the first time since 1998. During that season against the Washington Redskins, he ran 33 times for 189 yards, which at the time was the third-most rushing yards in a game by a running back in franchise history, only Tony Dorsett and Smith had better games. On May 13, 2004, he was waived after the Cowboys drafted Julius Jones in the second round and also took into consideration his production (3.5 yards per carry).