After Wales had beaten England at Twickenham for the first time in 20 years, Shaun Edwards launched into a rendition of Drifters' classic 'Saturday Night at the Movies'.

Yesterday it was more like 'Saturday Night at the Brewery' as the Wales squad celebrated their historic Grand Slam triumph at a private party hosted by Cardiff beer company Brains.

The celebrations continued in earnest all night and, for some of the players who were still in their black ties as the sun came up, well into today.

But who could blame them?

Barely five months ago Welsh rugby had hit rock bottom. They had been bombed out of the World Cup by Fiji and dropped to 10th place in the international rankings.

Today, they were standing proud - at least, those of them who could stand - as Grand Slam champions, most for the second time in four seasons.

So how on earth did they get from there to here?

The first answer is Warren Gatland. The second is Shaun Edwards. And the third is brutal hard work.

Gatland's biggest challenge when he took over as Wales coach in December was to bring authority, direction and stability to a rugby nation which had drifted horribly since the 2005 Grand Slam.

Despite the sponsor's logo which has been emblazoned on their jerseys for the last three seasons, Wales' biggest failing at the World Cup was a lack of brains.

Their headless-chicken performance in the pivotal World Cup pool game against Fiji resulted in a thrilling spectacle - one of the best matches you will ever see, in fact - but also in defeat and elimination.

Gareth Jenkins was sacked having never managed to convince the senior players of his game-plan. Consequently Wales spent 18 months without a clear tactical approach and lost 13 of their 20 Tests.

Under Gatland the whole Wales environment was shaken up. Training has been more intense than any of the players can ever remember and a new emphasis was placed on standards, on fitness, on attitude and on commitment.

For it to work, the squad had to buy into the approach and captain Ryan Jones played a key role in that, leading from the front and demanding his players follow.

''It's about intensity and making sure we work under pressure. There is absolutely no excuse for a player pulling on an international jersey and not dying for the cause,'' said Gatland.

''If I can create that environment then it's going to go a long way to us getting some results on the field.''

And it worked like a dream. If Wales relied on good fortune to win at Twickenham, then it was nothing but sheer heroics that earned them victory over France and sealed the Grand Slam.

The defence that leaked points in the World Cup was reinvented by Edwards and Wales set a new Six Nations record by only conceding two tries in the whole tournament.

France enjoyed about 70% of possession and Wales had to make 128 tackles but could not be broken open. Again, Jones led from the front, making 20 of those tackles.

He was an inspired choice as captain and persuading Martyn Williams to come out of retirement was also key. He enjoyed a huge game against France.

Gatland and Edwards have also brought the best out of players whose Test form has suffered in recent years.

Gavin Henson, one of two defence captains, has been reborn under the Gatland regime having never found favour under Jenkins.

Lee Byrne has been arguably Wales' most improved player at full-back while Gethin Jenkins was back to his marauding 2005 best.

Gatland believes Wales deserve to have at least a dozen players on the Lions tour to South Africa next year - and he may well be the one to take them out there. Ian McGeechan, the Lions legend, boasts a strong case to attempt a repeat of his 1997 Test series triumph.

But the Lions cannot afford to overlook the Welsh dream team of Gatland and Edwards - especially if they want to enjoy a few victorious Saturday nights on the High Veldt.