Millions of basketball fans watching the NBA finals around the world probably experience idle seconds when they fleetingly wonder how they would fare if they somehow found themselves out on that floor with the gods. There are many very good ball players and why not daydream about throwing an alley-oop to LeBron James or guarding Steph Curry, the mesmerising point guard for the Golden State Warriors. Perhaps the closest those fans will ever come to embodying that experience is through channelling the unlikely presence of Matthew Dellavedova, a small, bearded and almost entirely unnoticed NBA journeyman – until this season's play-offs began.

If there has been something almost spiritual about LeBron James's quest to deliver a first-ever NBA championship for Cleveland with three extraordinary wilful nights against Golden State, then the emergence of Dellavedova as his heroic sidekick has been something of a comic outrage. His performances were the cause of a notable reference to NBA basketball in the rarefied pages of the New Yorker, albeit in the space reserved for its absurdist-humorist Andy Borowitz, whose story was headlined: 'Dellavedova breaks arms, legs, neck: will play game four" and quoted Cleveland's head coach David Blatt as hailing his plucky point-guard as being "the kind of blue collar, steel worker lunch pail smokestack guy who won't let a little full-body cast slow him down."

Toughest route

Dellavedova is Australian and made it to the NBA through the toughest route possible. He was undrafted in college – meaning no NBA scout rated his chances – but did enough in the 2013 summer league to convince the Cavaliers to sign him as a reserve on a two-year contract. Then, the Cavs’ were just another NBA team but the return of James instantly transformed them into the most watched and talked about side in the league. They made it to this year’s finals despite the steady elimination of their other bona-fide superstar, Kyrie Irving, and their other reliable scorer,

Kevin Love

, leaving it up to James to all but carry a roster of streaky misfits towards the championship.

Into the void stepped Mr Dellavedova. It is not that he doesn’t look like a basketball player: it’s just that he looks like a basketball player who wandered in from a Friday night pickup game and who has absolutely no business mixing it with the best in the word. The most casual sports fan would take one look at the television screen and think: okay, here are two big-time basketball teams, that must be LeBron James and . . . hang on, why’s that little beardy guy playing?’

Dellavedova constantly looks like he might lose control of the ball – but never does. His outside shot is a clunky heave – an affront in comparison to the lithe, lightning and effortlessly graceful form which Steph Curry has raised to art – but in game three, he nonetheless flattened Golden State with huge three-point shots. He hurls himself at loose balls with no regard for either his own body or those of his opponents: in the conference finals, Dellavedova ended the seasons of no less than two Atlanta Hawks stars by buckling their knees as he dove for possession. You could see even then that opposition players were regarding Dellavedova as a kind of moving hazard while also wondering how come he was even there.

Desperation rather than inspiration prompted Cleveland to not only start Dellavedova in game 3 of these finals but to have him guard Curry. Perhaps one of the reasons Curry played so poorly that night, shooting woefully, was he was in a sustained state of shock that the Cavaliers would dare to match such an obviously inferior player against him. It was little short of an insult. But then the improbable began to happen and kept happening. Curry struggled. Dellavedova didn't so much guard him as stalk him, hustling and working and refusing to ever become demoralised and growing in stature as the Cleveland crowd warmed to the Australian's manic attempts to make the most of a once in a lifetime opportunity. His nickname –"Delly" – became common place and he received the imprimatur of a beaming LeBron in television interviews. The fascination with this supremely un-NBA like star soon circled the globe. Of all the comments, the one that best summed the Australian up was a tweet by a Matt Hinton, who wrote: "At all times Dellavedova is traversing multiple realities at once in which he is simultaneously inept and unstoppable."

Every single time Curry took possession, you were waiting for him not just to score on the plucky underdog but to do so in a way that would horribly expose his shortcomings and make plain the gap between where Dellavedova’s skills ended and Curry’s began.

Bad dream

Dellavedova scored an improbable 20 points in game 3, the most unbelievable of which came in the closing minutes of the fourth quarter when Curry, reaching around the Australian, almost stole the ball only to stumble into his opponent when Dellavedova lost his footing, got fouled by Curry and flung up a shot-to-nothing off balance, which inevitably caromed off the back board to give the Australian the score plus a foul shot. By now, Curry looked like a man who was walking through a bad dream. Dellavedova’s antics were sufficient for thousands of weekend warriors watching from bar stools or the sofa, to re-evaluate the lost greatness of their basketball careers. Delly prompted a universal trigger thought: If this little guy could do that to Steph Curry, what might I have done?

The only legislation lay in the fact that Curry’s way of playing is so heightened that it shouldn’t work. James’s position as the best player on earth is based on many qualities but his daunting strength and athleticism are central to those. Curry is a teenage-skinny 6’3” and defies double teams and physically stronger opponents by letting fly with fade away, off balance threes and uncanny teardrop shots which are the last word in finesse.

Curry knew that as a player, he exists on a different plane to Dellavedova. So too does Dellavedova. That was why watching Dellavedova getting under the skin and bothering Curry all night long made for such a fascinating and surreal spectacle.

Of course, it cannot last. The Warriors won game 4 in Cleveland and the series is level at 2-2 as the finals return to California for game 5 on Sunday evening. It is hard to escape the feeling that whatever elixir of inspiration and fate briefly elevated Matthew Dellavedova to frustrate and irk Curry has worn off. LeBron’s valiant attempt to almost single-handedly bring an NBA title to his home state may have disappeared with it.