Saunders, 31, in his first fight in a year, was too sharp and strong for his durable 38-year-old opponent, who was hurt several times throughout the contest.
Murray went down under a barrage of punches in the fourth round, but appeared to have lost his balance and no knockdown was given.
Saunders, who reiterated his desire for a blockbusting fight with Mexico's Saul Canelo Alvarez, extended his unbeaten record to 30-0 to join Josh Warrington as the current British boxer with the longest unbeaten run.
Saunders looked to force the issue from round one and the southpaw's jab began to find its target in the second, with Murray struggling to find his range.
The champion looked the classier fighter and landed several left hooks to Murray's body before landing two big left uppercuts in the third round.
Saunders' superior hand speed was telling, while his jab pierced Murray's guard again in the fourth, which he comfortably lost.
Murray had been pushed back on to the ropes and found himself on the floor after holding, but a knockdown was not awarded.
Murray appeared hurt at the start of the fifth, but Saunders eased off the pace and continued to dominate in the sixth as he fired off more two-handed combinations.
Saunders caught his man again in the seventh and although Murray stepped up his work rate in rounds eight and nine, he never troubled the champion.
More body shots and upper cuts rained in on Murray in the closing rounds as Saunders upped the tempo and continued to hit the target with clean shots from all angles.
"I've been out over a year now and it's like boxing in a cemetery," Saunders told Sky Sports. "I like to perform for the crowd, get up for it.
"Tonight I tried to set a rhythm, but he's a cunning old fox. He knows how to tie you up well.
"It's not a performance I'm going to be shouting people's names about because I've been out a year and I probably needed the rounds to be honest with you.
"He got through it, so fair play to him. I hope he has a good Christmas and he can go back to his family."