BRENDAN Gleeson has been for years a brilliant supporting character actor (casual cinemagoers will probably recognise him as Mad Eye Moody from the Harry Potter series).

In The Guard he gets a richly deserved leading role which is not only one of the best and most memorable of his long career but worthy of recognition come awards time.

He plays Sergeant Gerry Boyle, a small town cop in the west of Ireland. Boyle is unapologetically crass and lazy; he steals drugs from crime scenes for his own personal use, drinks heavily and unashamedly indulges in three-way sexcapades with hookers dressed as police officers.

But he’s also powerfully perceptive (sort of like an Irish Columbo), has an encyclopaedic knowledge of the arts, is kind to his dying mother and has irrepressible knack for infuriating his superiors.

News Shopper: MOVIE REVIEW: The Guard ****

Boyle’s quiet life is disturbed when a murder occurs in the parish. He quickly fingers a gang of surprisingly literate international drug smugglers (Liam Cunningham, Mark Strong and David Wilmott) but the case is handed to straight-as-an-arrow FBI agent (Don Cheadle), with whom he forms a grudging alliance.

The plot is familiar but the characters are unconventional.

News Shopper: MOVIE REVIEW: The Guard ****

Writer John Michael McDonagh (brother of In Bruges director Martin with which this film has several similarities) has crafted a funny, irreverent and memorable black comedy which takes great delight in pointing out and inverting many tropes of the genre.

Traditionally, you’d expect the fish-out-of-water character to be the hero (a character even goes so far as to point this out) but Cheadle is merely the foil to Gleeson, at whose unconventional approach he can only sigh and shake his head in weary disbelief.

News Shopper: MOVIE REVIEW: The Guard ****

Their relationship is judged perfectly; the dialogue is excellent and full of quotably memorable lines taking comedy pops at the clichés of the American cop shows, the buddy movie genre and small town Irish life.

The supporting cast are also superb. Liam Cunningham and Mark Strong are their reliably excellent selves.

Strong in particular is hilarious as a hard man with a bad attitude, practically radiating irritation.

News Shopper: MOVIE REVIEW: The Guard ****

If anything, they’re indulged a little bit too much and it’s a shame that Cheadle doesn’t get to be as funny as Gleeson – the middle section squanders the momentum which the first half built up so masterfully.

But it’s Gleeson’s performance which is the heart of the film - he’s both sympathetic and likeable even when at his most crass and he manages to keep both the characters and the audience guessing as to whether he’s an idiot or a genius.

One thing that is perfectly clear though is that The Guard is a sharply written, hugely enjoyable film; an unconventional and surprising black comedy that’s one of the funniest films of the year. Highly recommended.

The Guard (15) is released in cinemas today.