There's nothing like a Monday morning screening of Doctor Who – just yours truly and Richard Bacon off of the wireless in a viewing room – to set the heart racing. Emerging, shellshocked and somewhat slightly discombobulated into the bright lights and fruity hullabaloo of Berwick Street market, it somehow feels as though the world has changed. And maybe, in some small way, it just has...

After months of fevered speculation, the era of new Doctor Who showrunner Steven Moffat is finally with us. And every well-deserved hyperbole thrown at his awesome back catalogue of writing credits for the series – classic episode Blink, of course, plus The Empty Child, The Girl In The Fireplace, Silence In The Library, among others – may now have to be upgraded.

The reaction to Matt Smith's casting in the central role, as the replacement for the frighteningly popular David Tennant, was far from universally positive. To get this moment wrong would be to risk the show becoming a twee irrelevance or slipping into sci-fi Hollyoaks territory and there have been hints that a backlash was brewing. Much, then, is riding on the fifth series since Christopher Eccleston's Doctor met Billie Piper's Rose in a London clothing department store back in 2005.

The first concrete evidence of Moffat's approach as post-Russell T Davies supremo suggests that the gamble on casting the relatively unknown Smith is just one of a multitude of masterstrokes.

Cometh [opening episode] The Eleventh Hour, cometh the Eleventh Doctor, as any misgivings about 27-year-old actor Smith's ability to project the wisdom, wit and sheer wonder of a 900-plus-year-old Time Lord evaporate. Smith sparkles. He dominates from the very first scene, as the Tardis careers towards earth to the breathless flash forward to The Doctor's future adventures with Winston Churchill, River Song, the Daleks, Venetian vampires and those scary Weeping Angels.

Smith's high-octane patter is smart, his eyes convey an intelligence that is near impossible to fake and the rapport with co-star Karen Gillan is instantaneous. He also brings a welcome touch of bolshy impatience to the role, his performance, modelled in part, he says, on Albert Einstein, owing as much to Patrick Troughton as David Tennant.

Gone is the jaded, world-weariness that characterised Tennant's angsty latter years. No longer nursing broken hearts and yearning for Rose Tyler, the Eleventh Doctor has an exuberance that is anything but youthful, too busy excitedly exploring his new body and vowing to take Amy anywhere "so long as it is amazing", for regrets from past incarnations.

"New mouth, new rules," he chirrups, while feeding his post-regeneration hunger after crash-landing in a non-descript English village. There, a beautiful, sweet, friendship between a Doctor reborn and a little girl in dire need of adventure is created via a wonderfully simple plot device [we're keeping this as spoiler free as humanly possible] – Moffat making good on his promise to play with the possibilities of time travel. Companion Amy is shown to be a complex and slightly damaged misfit, a lost soul with compelling reasons for putting her trust in the oddball with a flying box.

Despite having to introduce us to a new world and new characters, the pace is relentless and introductions unclunky – thanks in no small part to the invisible hand of director Adam Smith. Heck, there's even time for a cameo from great friend of the Quietus Sir Patrick Moore and hints at a story that will run throughout the series, while Moffat also embraces the show's rich history – yes, even the Paul McGann days – with a scene to make long-term fans swoon.

Little wonder Smith chose to describe the showrunner as a "genius" who "can pluck a fairytale from his mind so brilliantly," when the Quietus met him a few months back at the BBC studio in Cardiff. Rather than present us with a finished version of the new Doctor, Moffat gives us the work in progress. We watch him develop and grow and choose who to ‘become'.

The Doctor takes time out from an enjoyable, if relatively jeopardy-free, race-against-time-to-save-the-planet-from-slimy-alien-menace plot to select an appropriate outfit for the occasion, picking up his outfit in a hospital changing room (as Jon Pertwee and Paul McGann have done in the past). As if by magic, a bow tie and braces appear and the scholarly stylings that give Smith's Doctor an uncanny, off-kilter yet on-trend look are complete.

That the Tardis – which is undergoing its own regeneration into a Steam Punk super-ship that we may get to explore in future episodes – is largely out of action and Smith's Doctor forced to survive on his wits alone, with an unreliable Sonic Screwdriver offering little assistance, only adds to his accessibility. The Time Lord humanised while we get to know him.

The best new Doctor since the last one is taking us on a thrill ride – now, who's for fish fingers and custard?