Nicky Cook today admitted he will face the biggest test of his ring career when he defends the WBO world super-featherweight championship against unbeaten Puerto Rican Roman Martinez.

Cook, with one defeat in 30 bouts, will put his title on the line on the same bill featuring Amir Khan's clash with Mexican legend Marco Antonio Barrera at the MEN Arena in Manchester on 14 March.

It was at the same venue that the 29-year-old from Stepney claimed his title so impressively against Scotland's Alex Arthur last September and he said: "I'm hoping it will be a happy return.

"Martinez hasn't been beaten in 22 fights and anyone with a record like that can pose a serious threat.

"But I've watched him on DVDs and I definitely believe he's beatable. He's tall and he likes to hit to the body, a lot like me.

"However, I'm strong at super-feather and I don't see the belt changing hands."