Warner completed 24-of-38 passes for 313 yards without an interception and became the second player in NFL history to throw at least 100 touchdown passes for two teams.
He threw 102 TD passes while playing in St. Louis (1998-2003).
Anquan Boldin made eight receptions for 116 yards.
Larry Fitzgerald and Early Doucet caught scoring passes.
Beanie Wells and Tim Hightower rushed for one touchdown apiece, and Mike Nugent added a 19-yard, second-quarter field goal for the Cardinals (10-5), who wrapped the NFC West with their third win in four games.
Keith Null completed 20-of-31 passes for 171 yards, one touchdown and three interceptions, while Josh Brown kicked a 33-yard fourth-quarter field goal for the Rams (1-14), who have lost seven in a row.