The C&G Trophy, formerly the Gillette Cup and NatWest Trophy, may not be the equal of football's FA Cup in terms of history or global profile.
But like the FA Cup, it has provided the game's lesser names with a chance to embarrass more illustrious opposition.
The competition was inaugurated in 1963 but this year will be the last chance for Minor Counties sides to upset the odds.
Ahead of the first-round matches on Tuesday and Wednesday, BBC Sport looks back at past 'giant-killings'.
1973 BRIAN LANDER, Durham v Yorkshire
Yorkshire became the first side to fall to Minor Counties opposition as Durham pulled off a famous five-wicket win at Harrogate.
Geoff Boycott was unable to save Yorkshire from defeat
Durham skipper Lander took 5-15 as the county side were bowled out for 135 and Russell Inglis (47) and Stephen Greensword (35 not out) helped knock off the runs with nine and a half overs to spare.
1974 IAN MOORE, Lincolnshire v Glamorgan
Martin Maslin and John Dale took three wickets each as Glamorgan were dismissed for 155 at Swansea.
Lincolnshire struggled to 80-4 in reply but an unbroken stand of 76 between skipper Moore (62) and Trevor Blades (50) saw them home by six wickets.
1976 ROBIN JOHNS, Hertfordshire v Essex
Essex looked set for an easy win after Ray East (4-28) helped bowl out Hertfordshire for 153 at Hitchin.
But they reckoned without off-spinner Johns (4-31) and slow left-armer Doshi (4-23) as they crashed to 120 all out and a 33-run defeat. Doshi went on to play Test cricket for India.
1984 MUSHTAQ MOHAMMAD, Shropshire v Yorkshire
Former Pakistan Test player Mushtaq shone with bat and ball as Shropshire pulled off a surprise 37-run win at Telford.
Mushtaq's efforts made him an instant Shropshire hero
He made 80, and was well supported by Stephen Gale (68), as they totalled 229-5 and then took 3-26 with his leg-spin as Yorkshire were dismissed for 192 in reply.
1985 STEPHEN GREENSWORD, Durham v Derbyshire
Derbyshire were bowled out for 171 despite 53 from skipper Kim Barnett, with Greensword (3-20) and Ashok Patel (3-34) doing the bulk of the damage.
Greensword then made 40 with the bat for Durham and skipper Neil Riddell wrapped things up with 49 not out as they reached 172-3.
1987 STEPHEN EDWARDS, Buckinghamshire v Somerset
Buckinghamshire enjoyed their finest hour at High Wycombe against a Somerset side including New Zealand Test star Martin Crowe.
Edwards was left unbeaten on 25 as they were all out for 154 but he dismissed Nigel Felton and Crowe in a spell of 2-14 from 12 overs as Somerset slumped to 147 all out, with Stephen Burrow taking 3-32.
1988 JOHN O'BRIEN, Cheshire v Northants
Northants came a cropper at Boughton Hall where they were all out for 161 despite their captain Geoff Cook carrying his bat for 53.
Spinner O'Brien took 2-19 and later came to the wicket as last man with 12 runs still needed as he and Andrew Fox guided them to a thrilling one-wicket win off the penultimate ball of the game.
1998 CRAIG WRIGHT, Scotland v Worcestershire
Bruce Patterson (71) and Mike Allingham (54) were the major contributors as Scotland posted a total of 244-6 in Edinburgh.
Wright's wickets left Worcestershire with too much to do
Wright then took 5-23, including the wickets of Graeme Hick and Tom Moody, to leave them on 98-6 and Worcestershire finished four runs short despite the efforts of Gavin Haynes (74) and Stuart Lampitt (54)
1999 FEIKO KLOPPENBURG, Holland v Durham
Durham joined the list of first-class counties in 1992, but seven years later received a taste of the medicine they had handed out to others in the past as the Dutch pulled off a five-wicket win at Amstelveen.
Kloppenburg took 4-25 as Durham were dismissed for 194 and then made 61 at the start of his side's successful run chase, with Luuk van Troost adding an unbeaten 59 in the final stages.
2001 HARSHAD PATEL & NATHAN ROUND, Herefordshire v Middlesex
Herefordshire appeared to have little chance after Middlesex reached 278-6 in their 50 overs at Luctonians CC despite the early dismissal of future Test star Andrew Strauss for four.
But Patel (68) and Round (66) shared an opening stand of 129 and Nick Davies (39 not out) saw them home on 279-7 with one ball remaining.
2004 ANDREW WHITE, Ireland v Surrey
Surrey's big reputation counted for nothing as the Irish pulled off a magnificent five-wicket victory with White taking 3-43 and then adding an unbeaten 20 as the game reached its climax.
Ireland will play a revamped C& G Trophy in 2006
The county side made 261 thanks primarily to Ali Brown (67) and Adam Hollioake (52) but Jason Molins launched the reply with 58 off 57 balls and Jeremy Bray weighed in with 52 as they got home in the 49th over.
2004 ANDREW PROCTER, Devon v Leicestershire
Last year's second giant-killing was the most exciting of all as Devon scraped through at Leicestershire's expense by virtue of losing fewer wickets at Exmouth.
Proctor took 3-26 as the visitors were all out for 161, but despite 42 from skipper Richard Dawson, Devon were hanging on at the end as Procter and Aqeel Ahmed played out the last few balls to reach 161-9.