THOR: RAGNAROK (12A, 130 mins)

Starring: Chris Hemsworth, Tom Hiddleston, Cate Blanchett, Idris Elba, Jeff Goldblum, Tessa Thompson, Karl Urban, Mark Ruffalo, Sir Anthony Hopkins, Taika Waititi. Director: Taika Waititi.

Three is the magic number for Marvel Comics' dreamy incarnation of the hammer-wielding Norse god of thunder.

Portrayed on screen since 2011 by Chris Hemsworth with flowing golden locks, gym-sculpted abs and laid-back Antipodean charm, Thor finally gets into an otherworldly groove in this third solo outing directed to the comic hilt by Taika Waititi (Hunt For The Wilderpeople).

The celebrated New Zealand film-maker and a trio of screenwriters adhere to a classic three-act structure for their heady brew of rip-roaring action adventure, bone-dry humour and dazzling spectacle that positions this gung-ho chapter closer to Guardians Of The Galaxy than its brawny predecessors.

In front of the camera, a holy trinity of Oscar winners chews the multimillion-dollar scenery with fervour, including Sir Anthony Hopkins, Cate Blanchett and an uncredited Hollywood star serving up theatrical ham in extremis.

Three members of the Avengers also make appearances to whet appetites for next summer's superhero smackdown, Infinity War.

The heavenly convergence of direction, writing and performance would align perfectly if Blanchett was allowed to fully inhabit her snarling villainess, who sets in motion the Ragnarok: a prophetic downfall of the kingdom of Asgard.

Instead, her merciless and supposedly unstoppable goddess of death is clueless and impotent for extended periods.

Loki (Tom Hiddleston) sits undeservedly on Asgard's throne, fashioning the kingdom in his narcissistic image, oblivious to storm clouds billowing on the horizon.

Noble sentry Heimdall (Idris Elba) no longer stands guard on the Bifrost Bridge - he has been usurped by an ambitious whelp called Skurge (Karl Urban).

Meanwhile, Loki's father Odin (Hopkins) has been ushered into early retirement, which inadvertently releases Hela (Blanchett) from her prison where she has languished for millennia.

An initial showdown between Thor (Hemsworth) and Hela culminates in victory to the vengeance-seeking goddess.

The fallen champion is cast out to Planet Sakaar, where he is captured by a mysterious merchant (Tessa Thompson).

She sells him to the Grandmaster (Jeff Goldblum), a hedonistic, gambling-mad Elder of the Universe, who presides over the Contest of Champions.

"People come from far and wide to unwillingly participate," deadpans the tyrant.

Consequently, the freshly shorn god of thunder is pitted against a smashing ally (Mark Ruffalo) in gladiatorial battle.

From its droll opening scene choreographed to the high-pitched howl of Led Zeppelin's Immigrant Song, Waititi's picture is a blast.

Hemsworth pokes merciless fun at himself, including one saucy interlude of near-the-knuckle barbs that intimates an unhealthy relationship between the hunk and an inanimate object.

The director scene-steals via motion-capture performance as an 8ft tall rock monster called Korg, who promises, "You don't need to be afraid ... unless you're made of scissors."

Two additional scenes are nestled in the heaving bosom of the end credits to ensure diehard Marvel fans leave on a giddy high.

Thor: Ragnarok rocks, and rolls with the punches. 8/10