Lancashire137 for 8 (Khawaja 67, Wagg 3-28, Hogan 3-33) beat Glamorgan 136 for 7 (Rudolph 67*, Clark 4-22) by one run
On a weekend when a T20 fixture designed to be played within three hours eventually sprawled over a day's deliberations and drama, Lancashire secured a place at Finals Day in circumstances which rivalled the county's glory years of the 1970s.
At the start of their 16th over in a rain-wracked game, Glamorgan were 100 for 3 and seemingly well placed to score the 138 runs they needed to reach English cricket's short-form showcase for the second time in their history.
Six balls later, after Jordan Clark had bowled Chris Cooke and Stewart Walters, and had David Lloyd caught at slip by Tom Smith, the visitors were 100 for 6 and behind on Duckworth-Lewis. Then it began to rain and play was held up for 45 minutes
When the game resumed Jacques Rudolph tried to make good the damage but the job was just beyond the South African. He ended unbeaten on 67 as Clark conceded 13 runs off the last over to finish with figures of 4 for 22. Since Glamorgan had required 15 off those last six balls, it barely mattered.
Before this quarter-final Clark had only taken four wickets in his 23-match Twenty20 career. Since he had also bowled Murray Goodwin, his match-changing triple-wicket maiden left him with figures of 2-1-4-4, hardly a conventional analysis for the Twenty20 game.
Home spectators who had watched quietly as Lancashire had been on the wrong end of most of the match, leapt to their feet as if galvanised by sheer joy. Suddenly the 23-year-old Clark had joined a gallery of popular memories which already included David Hughes' famous 24 runs off an over bowled by the late John Mortimore, Clive Lloyd's century at Lord's and Jack Bond's catch off Asif Iqbal.
It is some company; but then it was some over.
Only those gifted with uncanny powers could really have predicted the transformation in this game. Glamorgan's progress towards their target had seemed relatively trouble free as Jim Allenby's 38 had helped Rudolph make very satisfactory progress towards their goal.
Goodwin had then helped Rudolph add a further 28 in four overs before Clark bowled him for 17. Thus began an extraordinary few overs in what will surely come to be known as Clark's match.
"It was a case of sticking in there for as long as possible," said the hero of the evening. "The ball was tailing slightly with a little bit of damp around and it was case of going back to basics and hit the top of off stump. Keeping them to five an over wasn't going to win us the game and I was trying to make sure that if they missed I hit."
For Glamorgan supporters Lancashire's innings had been a delightfully low-key affair, significantly devoid of the big overs or bursts of acceleration that characterise substantial T20 totals.
Watched by a crowd of around 1500 spectators, which was perhaps eight thousand fewer than officials had been expecting had the game gone ahead on Friday evening, the home side's batting lacked the big-hitting gusto that had marked their previous short-form efforts this season.
Much of the credit for that should go to a disciplined visiting attack which knew its job and was backed up by some fine fielding. Left-arm seamer Graham Wagg removed openers Ashwell Prince and Tom Smith for single-figure scores to limit Lancashire's ability to exploit the Powerplay; off the last ball of the eighth over Salter induced Karl Brown to walk past a quicker delivery and be stumped by Mark Wallace for 15.
That wicket left Lancashire on 59 for 3 but the most spectacular dismissals were yet to come. On the day when he became the oldest cricketer to play in the English domestic T20, 41-year-old Goodwin dived athletically at backward point to remove Lancashire skipper Paul Horton for 3; eight overs later 36-year-old Dean Cosker's smart catch off Usman Khawaja's ferocious square drive was equally impressive.
Khawaja's 67, made off 54 balls and spanning nearly 15 overs, had anchored his team's effort. But at no point did the Australian dominate a Glamorgan attack which had offered few loose deliveries to batsman clearly frustrated by constraints.
Glamorgan's spinners bowled nine of the 20 overs with offspinner Salter conceding just 19 off his allocation and 14 of the 35 runs Dean Cosker yielded coming off one over in which Khawaja hit Lancashire's only six. A late clatter of wickets saw Wagg claim his third wicket and Hogan's successes in his final over left him with 3 for 33.
Few pundits reckoned that Lancashire total of 137 represented prosperity. It was, however, just enough.