Leadbitter goal keeps Black Cats purring
Murphy struck from close range after 17 minutes for his first goal in 13 appearances and Leadbitter doubled the advantage during five minutes of first-half stoppage time with his second goal for the club.
Substitute Ray Jones pulled one back but the Black Cats, who were bottom when Keane took charge in August, stretched their unbeaten run to four games to leapfrog Rangers in the table.