Gloucestershire 267 for 2 (Klinger 137*, Marshall 78*) beat Yorkshire 263 for 9 (Lyth 96, Howell 3-37) by eight wickets

His stint in England officially completed, Michael Klinger had confirmed his departure for Australia after guiding Gloucestershire to the Royal London semi-finals by suggesting that he might return if they got to Lord's. Back in Perth, the lure of a final was impossible to resist. He chatted to his wife, got back on a plane and played the innings to get them there himself.

He has been playing innings of quality all summer long. Klinger's run in the 50-over competition has been remarkable: three hundreds in his last five innings, against Somerset, Durham and, finally, Yorkshire, his 137 not out from 145 balls, guiding Gloucestershire to an eight-wicket win at Headingley with 19 balls to spare.

Yorkshire made only 263 for 9 when they looked set for 300, from which point Klinger was clinical enough to compute victory without ever needing excess. It was a long-haul innings to follow a long-haul flight.

"I have travelled a long way for a day's work but it has been a great day for the club and the players," Klinger said. "I would have felt pretty guilty if I hadn't come back. It was a no-brainer. Thanks to the club for flying me back for five days and allowing me to see my wife and kids. I am going to wait around for the final. I have put myself through a Western Australia fitness camp to make sure my coach, Justin Langer, doesn't get too upset with me when I get back home. I think it's our time."

There were around 8,000 at Headingley on a gorgeous late summer's day, most of them anticipating the next stage of a potential Yorkshire double, but instead they endured an innings of draining authority on a dry surface as Klinger took Gloucestershire to Lord's to face the winner of Monday's second semi-final between Surrey and Nottinghamshire at the Kia Oval.

Yorkshire's semi-final record remains dreadful: 16 defeats in 19 stretching back to a time when Margaret Thatcher had just been elected as prime minister in 1979.

Klinger has dominated Gloucestershire's one-day season to an extraordinary extent. He has been the most compelling story of the county season. He goes to Lord's with three hundreds and an average of 132.75 in the competition. He averaged 81.75 in the NatWest T20 Blast, another three hundreds gained, and before the English season, he was the leading run-scorer in Australia's Big Bash.

"We need Klinger": The imperative was there for Yorkshire from the moment he took guard. "We need Klinger": It began as a logical statement of fact, grew into unease, then desperation and finally taunted every Yorkshire fielder with the knowledge that as much as they wanted Klinger it would never happen, as distant from actuality as wanting to own a Caribbean island or to take wings and fly to the moon.

Yorkshire's attack appeared inadequate. Lacking Liam Plunkett and Adil Rashid on England duty, they also chose to omit two bowlers at the centre of their expected Championship triumph - Ryan Sidebottom (who has long dispensed with one-day cricket) and Jack Brooks, a more debatable omission in a semi-final when the Championship is as good as won. Remove those four and what was left was an insipid attack which gave an inexperienced captain in Alex Lees no room to manoeuvre. It was loyalty gone too far. This was a game that explained why Yorkshire, as strong as they are, have signed David Willey.

Klinger's judgment and placement was impeccable. On the rare occasions Lees tried to squeeze the game, Klinger chose his moment and pummelled one down the ground. He lost Chris Dent to the last ball of a well-judged Powerplay, Matthew Fisher striking his off-stump, and Gareth Roderick dragged Will Rhodes to mid-on to encourage Yorkshire hopes that Gloucestershire, too, would unravel as the ball softened.

But Hamish Marshall proved a redoubtable ally in an unbroken third-wicket stand of 177 in 28 overs - a Gloucestershire record stand against Yorkshire in one-day. Marshall, 78 not out from 75 balls, was not quite as stylish perhaps, but he was equally adept. Both played what Klinger rightly called "high percentage cricket". He rounded it off by lifting Fisher straight for six.

Gloucestershire have not won a one-day trophy since 2004, the end of a period when they dominated the limited-overs game. Ian Harvey, one of the stalwarts of that era, is now back alongside Richard Dawson as assistant coach, and if there is no longer the sight of Jack Russell yapping away behind the stumps, maintaining intensity in his washed-out sun hat, Klinger is the lynchpin in a side rediscovering its self-belief.

That was illustrated by the way Gloucestershire dragged Yorkshire back from 159 for 2 with 22 overs remaining. Adam Lyth had played with verve for 96, his Ashes failures cast aside as he drove on the up with vim, but pulling James Fuller in search of his hundred, he fell at long leg.

Step forward Benny Howell: one wicket and 12 overs before today in the competition. His surreptitious medium-pace made better use than any Yorkshire bowler did later, Gary Ballance chipping a return catch to become one of his three victims.

There was a vital wicket, too, for Liam Norwell, who should have caught Jonny Bairstow, on 34, off his own bowling only to inexplicably drop the ball to the floor. He might just have persuaded the third umpire that he had the ball under control for long enough, only to compound his error by throwing his hands to his face and thereby pronounce himself guilty. Norwell, to his immense credit, withstood an over of baiting from the West Stand, smiled affably at his mark at the start of his next over and removed Bairstow with an inswinger without further addition.

Klinger then knew that a Gloucestershire recovery was possible. "After the first 10 or 15 overs I thought it wasn't the best call to bowl, but we have chased well in both formats this season," he said. "The credit today has to go to our bowling attack. That second 25 overs was the difference to us chasing 260 not 300. I think it's our time."

Yorkshire had suffered a similar middle-order collapse in the quarter-final against Essex only for Plunkett and Rashid to get them out of jail. That escape route no longer existed. Klinger duly took command. Lyth's unexpected appearance as an off-spinner unsettled him enough to get down to the non-striker's end to have a look, Rhodes made him hurry on 92, with a direct hit, but each successive drive told of a batsman whose memorable season has not been prone to error. Gloucestershire will pray that he can do it just one more time.