Dayton is resigning in order to pursue other professional non-football options.
Dayton, who was hired by Lambert July 1, 2012 as part of the 49ers first-ever coaching staff, spent the 2012 season coaching players in preparation for the 2013 inaugural season. This past season, he helped the 49ers to a 5-6 record in that inaugural season.
"We appreciate all that Drew has done to help get our program started," said Lambert. "He worked hard for our program and we wish him the best as he pursues other options outside of coaching."
Dayton is a 2003 Wake Forest graduate who helped the Demon Deacons to the victories in the 1999 Aloha Bowl and the 2002 Seattle Bowl as a member of the secondary. He began his coaching career at Lenoir-Rhyne in 2003 and spent six seasons at Duke as both a graduate assistant and defensive quality control before joining the 49ers.