St Helens middleweight Martin Murray is fiercely focused on springing a huge upset when he tackles homecoming hero and WBC champion Sergio Martinez in Buenos Aires on Saturday night.

Murray, an undefeated former British and Commonwealth title-holder, is a massive underdog ahead of his trip into the lion's den of the Estadio Jose Amalfitani, where a partisan crowd in excess of 40,000 will give their vociferous backing to pound-for-pound star Martinez.

The 38-year-old is boxing in his native Argentina for the first time since February 2002 - jobbing bouts in the Spain and the UK followed before a move Stateside to complete a tirelessly earned journey to world-title glory for one of boxing's most highly respected practitioners.

In 28 bouts since beating countryman Francisco Antonio Mora, Martinez has tasted defeat only once - a highly controversial points defeat to American Paul Williams in December 2009 that was avenged by a brutal one-punch knockout triumph a year later.

More recent successes have come with wins over British duo Darren Barker and Matthew Macklin, both halted in 11 rounds following earlier encouragement against the lavishly gifted southpaw, but Murray is confident he can go one better than his domestic rivals.

"I've not come over here to lose or to make numbers up," said the 30-year-old during conference call to round off a hectic promotional schedule. "I've trained hard and I truly believe I can win.

"Sergio's a great fighter who I've looked up to over the past couple of years but I truly think it's my time.

"Whatever Sergio brings on Saturday I'll be ready for and I'm just looking forward to being in a great fight."

Murray finds himself in the thick of a highly-competitive world middleweight scene on merit, having previously performed impressively when thrown into a tough assignment on foreign soil.

Few observers gave a fighter barely tested beyond domestic level much hope when thrust into a challenge for then WBA ruler Felix Sturm's belt in Mannheim, Germany 16 months ago.

But Murray grasped his opportunity impressively, doing enough in the eyes of many to dethrone the experienced champion before a 12-round draw was announced - the only time he has failed to emerge victorious in 26 professional contests.

"The Felix Sturm fight was a great learning experience for me," he explained. "Loads of things I learnt there I'm going to be bringing into this fight with me.

"I know Saturday is going to have to be the best performance from me but it's a performance I'm well capable of producing.

"The fact that it's against such a great fighter in his homeland has got me up for it. I have to raise my game and will raise my game on Saturday.

"I'm looking forward to putting all my hard training to good use and coming out victorious."

Despite a seemingly perfect build-up under the watchful eye of Salford-based trainer Oliver Harrison, such an outcome remains a tall order.

Martinez has confidently predicted ending his opponent's challenge after eight rounds but, perhaps with a slight air of contradiction, insists he will take nothing for granted on fight night

"This is going to be a very tough fight, I am fully aware of that," said the clear favourite.

"I know how people can predict but when you get in the ring it's a fight.

"This guy deserves to be in the ring with me so I'm prepared for a very tough fight."

A masterclass almost turned sour for Martinez last time out when he was badly floored and hurt in the final round against Mexican rival Julio Cesar Chavez Jnr seven months ago.

The upshot is Murray could face the most polished version of the 54-fight veteran to date."I'm very conscious that you always have to improve," Martinez added.

"I don't think it's convenient to say those things I have worked on (but) I guarantee this fight will end with a knockout."