Quite why the former Dire Straits frontman and the 20th century pop colossus who only last week added runner-up in the Nobel prize for literature to his accolades are touring together is, at first glance, a mystery.
But their collaboration in fact stretches back to 1979, when Dylan caught Knopfler's fast-rising band live in Los Angeles and asked him to play guitar on Slow Train Coming.
Four years later, Knopfler produced another Dylan album, Infidels, and played on the hallowed Blind Willie McTell, which misty-eyed Dylanologists decree his best song since the early 1970s. It's both baffling yet typical that the two men don't share the stage together, and the song remains unplayed.
With a small section of the venue unsold, it's hard not to suspect that in recessionary Britain even legends have to resort to a buy one, get one free offer, although this is an intriguing pairing of two of rock's most willful contrarians.
Certainly, being a Dire Straits fan is never easy. Ridiculed by TV comics as Dire Stuff even in their multimillion-shifting heyday, repeated critical attempts to rehabilitate the understated beauty of songs such as Romeo and Juliet haven't dented their unassailable lack of cool.
Meanwhile, Knopfler has turned his back on the band for so long that former members have started to play the songs without him (as the Straits).
Bald and stocky, with no longer any need for that trademark headband, Knopfler now looks more like a bricklayer than the 80s stadium rocker people remember, and ignores his back catalogue with impish glee.
After a stream of beautifully played new songs eventually lead one exasperated punter to yell "Play something we know", the Knopf raises one eyebrow and introduces a ditty about the joys of sleeping rough in graveyards – "It's nice and warm down there with the bodies."
Dire Straits's Brothers in Arms and So Far Away have to be virtually dragged out of him, but perhaps this famously grumpy rocker is enjoying himself more than he likes people to know.
Dylan fans, however are long used to such a runaround, with his dark classics rendered so unintelligibly in some recent tours they could be the works of Donald Duck.
Still, that voice was always challenging, even in the 60s. Here, it takes three songs to warm up and even then sounds like Tom Waits doing a panto villain.
But at full pelt, Dylan's theatrical gurgle gives a new and weirdly compelling energy to Ballad of a Thin Man and a sublimely remodelled Simple Twist of Fate.
The 70-year old's gnarled chops will always prompt debate, but a fantasy set list is hard to fault, and A Hard Rain's Gonna Fall, Tangled Up in Blue and other rock stone tablets are delivered alongside the newer likes of Summer Days by an energetic young band of gunslingers at ear-rattling volume.
Highway 61 Revisited is reworked so thoroughly it could be the M62, but from the comical intro tape about "emerging from a period of substance abuse in the 60s and finding Jesus in the 70s" to a storming All Along the Watchtower, the nimbly dancing septuagenarian seems to be again enjoying being Bob Dylan.
When Manchester roars along with Like a Rolling Stone, it honours the enduring uniqueness of the man even his famous support act refers to as "Mister Bob." At Cardiff Arena (029 2022 4488) on Thursday and touring until 21 November. Details at www.bobdylan.com
