Carl Frampton has lost his WBA featherweight title on the first defence after Leo Santa Cruz put in a thrilling display in their rematch in Las Vegas.

The Northern Irishman stunningly took Santa Cruz's belt in July, but the Mexican deservedly regained it with a majority points decision at the MGM Grand that ends Frampton's unbeaten record.

One judge scored the contest at 114-114, but the other two gave it 115-113 in Santa Cruz's favour and the two fighters are set to slug it out once more to complete the trilogy, possibly in Belfast.

The tone was set with an explosive round as both men came out swinging wildly, but it was Santa Cruz, improved massively from the Barclays Center fight last summer, that connected with the most and he shaded the second round as well.

The two boxers in action (Getty)

Frampton began to find his range, but Santa Cruz was relentless with a productive jab and he continued to outscore the champion through the middle rounds of the fight.

Frampton won some rounds back and finished strongly in the 12th in a bid to claim a knockout, but Santa Cruz held firm to take the belt and hand down a first defeat in 48 fights to his opponent.

Afterwards, Frampton called on the Mexican to complete the trilogy with a final showdown in Belfast.

"I hope so, I hope he is a man of his word and we can do it in Belfast," he said on Sky Sports 1. "I have come to the States twice. We could do it four, five, six times. I hope we do it again.

Santa Cruz looks to land a blow against his opponent (Getty)

"I am deeply disappointed but let's have a trilogy and have our names linked together forever and hopefully I can win 2-1."

Frampton also admitted that he had been caught out by his opponent's tactics on the night.

"I think it was the right decision, I thought it was close," the Northern Irishman added. "He frustrated me at times, I didn't expect that game plan, the boxer got out-boxed by the brawler. I thought it was the right decision, I hope we can do it again, it was a close fight.

"I have got no excuses, I feel I want to say sorry, I feel like I have let everyone down. The best man won on the night. I am gutted. It was my fault."

Santa Cruz admits he had to fight against his instinct as well as Frampton.

"I worked hard and did what I had to do," he said. "I fought a great fighter and let's make a third fight. He is a great fighter and a great counter-puncher. It was tough to change my style, in my head I wanted to go for it, but I was told to box him and that's what I did.

"I am a man of my word. We are both great fighters, we deserve it and let's go again."