Saul "Canelo" Alvarez demolished Turkey's Avni Yildirim in three rounds to retain his WBC and WBA super middleweight titles by knockout on Saturday.

Mexico's Alvarez dominated underdog Yildirim from the opening bell and sent the Turk crashing to the canvas with a crisp left-right combination in the third round at Miami's Hard Rock Stadium.

The outclassed Yildirim then failed to emerge from his corner for the fourth round as Alvarez once again demonstrated why he is regarded as the best pound-for-pound fighter in boxing.

Alvarez, who improved to 55-1-2 with 37 knockouts, had got back into the ring on Saturday a little over two months after beating Britain's Callum Smith in December.

After the fight, promoter Eddie Hearn said the 30-year-old Mexican star will next seek to add the World Boxing Organisation belt to his collection with a May 8 fight against Britain's Billy Joe Saunders.

Saturday's fight might well give Saunders pause for thought as Alvarez produced his trademark blend of technical skill and punching power to overwhelm Yildirim.

The Turkish challenger, fighting for the first time in two years, looked hesitant from the outset as Alvarez landed an array of hooks to the body and uppercuts to easily win the first round.

The second round followed an identical pattern, with Yildirim barely offering any kind of resistance as Alvarez worked his opponents ribs mercilessly.

The end came after a third round where Alvarez once again went on the attack. 

A straight left from Alvarez smashed through Yildirim's guard and landed on his chin and the following right sent the Turk rocking backward to the canvas.

Although Yildirim hung on for the remainder of the round, the end was nigh. As Yildirim slumped on his stool, trainer Joel Diaz could be heard telling his fighter he would give him only one more round before throwing in the towel.

In the event, it never got that far as Yildirim failed to come out for the fourth to hand Alvarez victory.