Unfolding almost in real time, 16 Blocks dusts off the plot of the 1977 Clint Eastwood chase thriller The Gauntlet to play an exhilarating game of cat and mouse on the streets of New York City. The mouse or more correctly mice are a grizzled detective and his fast-talking prisoner; the hunters are the city's corrupt cops, who will stop at nothing to conceal their guilt, even if it means executing one of their own.

Director Richard Donner, who gave us the Lethal Weapon series, directs the action sequences with his customary aplomb, including a smashing' chase on a bus with punctured tyres and a shoot-out in a low rent apartment block. Where 16 Blocks excels, however, is the decision to cast Bruce Willis against type as an overweight detective who has almost given up on life, and himself.

"Days change, seasons change, people don't change," he says morosely. Pouring with sweat, and spluttering and wheezing as he struggles for breath, Willis's cop is a man on a downward spiral to oblivion, numbing the pain and his guilt with copious bottles of alcohol. His self-worth and self-esteem are in tatters, he has a gammy leg, and has no social skills, especially when it comes to humouring Mos Def's street punk, 5ft 10in of verbal diarrhoea whose squeaky voice suggests a man who has been inhaling helium since birth.

Barely awake and desperate to sleep off a hangover, grizzled NYPD detective Jack Mosley (Willis) is far from pleased when he is assigned babysitting duties. Petty criminal Eddie Bunker (Def) is due to testify at 10am before a grand jury and someone needs to escort him the 16 blocks from lock-up to the courthouse. Jack begrudgingly accepts, not that he has any choice, and places Eddie in the back of his car for the 15-minute drive.

Stopping off to pick up breakfast (a bottle of liquor), Jack is shocked when two assassins attempt to kill his prisoner. Heading for the safety of a nearby bar, Jack calls for back up and homicide detective Frank Nugent (David Morse) arrives with officers Jimmy Mulvey (Cylk Cozart) and Robert Torres (David Zayas) in tow. But then the trouble really begins because Eddie realises that the men he is due to testify against are standing before him.

Written by Richard Wenk, 16 Blocks slowly gains dramatic momentum then sustains the tension until the closing frames, when Jack most somehow deliver Eddie to the courthouse before the 10am deadline. The banter between the lead players is lively and the relationships well developed, even though Wenk can't resist a smattering of cheese at the end. Willis delivers a performance of few words while Mos Def barely pauses for breath during his twittering, running commentary.