Even at this stage, the bare details do little to explain the sheer spell-binding quality of the innings which Ryan Watson produced when the Scottish Saltires locked horns with Somerset at a soggy Grange in May 2003. Just 48 hours earlier, the same combatants had met in the NatWest Trophy at the Edinburgh venue, with the Englishmen cruising to the most comfortable 10-wicket triumph that it would be possible to envisage, fuelled by the potent run-scoring of their prolific Anglo-Australian openers, Marcus Trescothick and Jamie Cox. Yet, if anybody doubted the uncanny ability of sport to serve up glorious tales of the unexpected, they should have been present when the sides squared up again.

The first wonder was that the Totesport League contest even started, let alone finished in scenes of clamorous celebration from the majority of those who braved the elements, while the skies dumped their worst over Stockbridge. For much of the afternoon, it seemed pointless to contemplate any action, and, but for Somerset's determination to stick around in pursuit of what they assumed would be another stroll in the park, the umpires would probably have abandoned the proceedings. But eventually, at after 5.0, the conditions improved, it was announced that the match would be a truncated affair, with both sides batting 16 overs, and Somerset's openers soon marched out to the crease and began putting their opponents to the sword in the formidable shape of Trescothick.

The former England Test star returned to where he had left off in the previous demolition, smashing his path to 80 from just 44 deliveries, including six fours and five 6s, and with the Cidermen's Ian Blackwell offering aggressive support with 34 from only 15 balls, the county personnel eventually bludgeoned their way to a formidable tally of 179 for 3, and Paul Hoffmann, who conceded just five runs from his three overs, was the only bowler to escape the muscular brutality of the professional ensemble. But, in this instance, the Scots were able to fight fire with fire in the blazing intensity of Watson, the little Zimbabwean, with the nickname "Rhino", and the Helensburgh-born James Brinkley. A further rain interruption left the Saltires requiring 180 from just 15 overs, which, frankly, seemed like mission impossible. But thankfully, nobody had conveyed that message to Watson.

"At the interval, we probably thought we had nothing to lose, and we knew we had to whack it from ball one, but the thing about that Scotland side was that we were a pretty confident group, [the coach] Tony Judd was excellent at instilling motivation and belief, and we had already beaten Durham [in their maiden game in the tournament], so we went out with the attitude that we would put bat to ball and see where it got us," said Watson, who subsequently captained his adopted country, turned out for them at the 2007 World Cup, and now works as a director with the IT recruitment company, Entrust People.

"We opened with myself and Greig Williamson, but it was when Brinks came in at No 3 that the innings really gathered a lot of momentum and, in a strange way, it took some of us the pressure off me, because he was such a clean striker and, suddenly, we were close to, if not quite up with, the required run rate. This was in the days before Twenty20, but we realised there was no option but to go for our shots and Brinks did that, with a string of boundaries [there were four 4s and two 6s during his knock of 48 in only 27 deliveries]. What I can remember is that we were always determined to go for it and the cheers from the supporters lifted us as well. Most of us had only recently started playing for Scotland and we had little or no experience of losing to the counties in these games. So we simply adopted the approach we would play every ball on its merits."

That maybe sounds simple, but it doesn't do justice to the swash-buckling nature of Watson's bravura performance as he moved through the gears, pulling, driving and cutting with such tremendous force that Somerset barely knew what had befallen them. One by one, a decent county attack, featuring the likes of Nixon McLean, Richard Johnson and Ian Blackwell, were despatched to all parts of the Grange as if it was the easiest thing in the world and the Saltires were flying! On the sidelines, a number of their fans kept awaiting a collapse, but even the pessimists' mood was transformed when Watson took a special liking to the gentle spin of Keith Dutch and clobbered the hapless patsy for one, two, three, four successive sixes into the adjacent tennis courts at the ground to leave the shattered bowler with the unenviable analysis of 2-0-48-0.

By this stage, any trace of sangfroid had vanished from the visitors, who shuffled their bowlers around to no significant effect. On the contrary, Watson, who had powered to his half-century, sped to three figures so quickly that his hundred was one of the fastest in the history of cricket and when he eventually reached his ton, from just 44 balls, the Tartan-clad aficionados, who had dared to dream, were delirious. Somerset, so clinical with the bat, were shot and it was fitting that the Scottish skipper, Craig Wright, should strike the winning runs for his team, with three deliveries to spare, and six wickets in hand.

At this distance, Watson, who has retired from international duty, but still turns out occasionally for East of Scotland club, Glenrothes, does not pretend he could perform with that swagger and panache on a daily basis. "There are afternoons where you are in the zone and the ball comes sweetly off the bat and you have to try and make the most of them," he recalled. "Every so often, you have a perfect day and that was one."

Yet, as his captain, Wright, told me, Ryan might be selling himself a little short with that assessment. "I believe, during that time, along with [Kenya's] Steve Tikolo, that Ryan was the best batsman in Associate cricket and it was an unbelievable effort against Somerset," declared Wright. "They had absolutely annihilated us in the NatWest Trophy on Wednesday, and Marcus was in brilliant form again on the Friday, but Ryan's display surpassed that comfortably, which shows you how well he played. Watching him really gave us all the belief that we could do more than simply compete at that level."

Thereafter, the Saltires endured contrasting fortunes in their jousts with the counties, registering the occasional victory, but more frequently being overpowered by their rivals. But, as Watson proved emphatically, there were instances where the underdogs could seize the ascendancy by the scruff of the neck and prove their mettle in the heat of battle. All of which explains why anybody who witnessed his century will never forget it.