He went to Tyneside in the early days of professionalism and helped turn Newcastle Falcons into champions of England, one of the more improbable feats of the late 20th century.
Five months into the 21st, he had inspired Northampton into defying the odds to overcome Munster in Twickenham's first European Cup final.
By then he and his Samoan team had left an indelible mark on the global stage, going as far as the knock-out stages of the 1995 World Cup and giving the Springboks a serious run for their money.
Two decades later and Lam is still breaking new ground, this time on the western rim of Europe.
Connacht go into Round Four of the GUINNESS PRO12 as one of only three teams to have won their first three matches, their best start for more than ten years.
Between last Friday night and late on Saturday afternoon they could be found at the top of the heap until first the Warriors and then the Ospreys overtook them with bonus-point wins.
Not for nothing does Lam describe himself as a 'vision person'. Topping the table, however briefly, was probably something he had not envisaged, least of all given the injury toll and the forbidding nature of the opposition in Galway last Friday night.
The Sportsground packed to the rafters is no place for the faint-hearted, especially when the squalls sweep in off the Atlantic.
Leinster had travelled across country knowing only too well what awaited them, arming themselves with eleven internationals in their starting XV and three more on the bench.
For all that quality and the pragmatism which gave them a nine-point advantage downwind, Leinster still wound up as so much grist to the Connacht mill.
Kieran Marmion's dazzling long-distance solo strike for the only try of the night and Jack Carty's conversion ensured another famous win.
For those who relish the prospect of the unfashionable outsider rising up in fearsome protest at their lot in life, Connacht are the team of the moment.
While it is absurdly early for any conclusions to be drawn as to where they will finish, one can be made without fear of contradiction.
In putting a glorious end to a lengthy run of defeats at the hands of their provincial neighbours - north in Ulster, east in Leinster and south in Munster, Connacht have served notice that they intend rearranging the ancient order.
Lam would have had that in mind when he made the longest of hauls from Auckland to Galway two years ago.
"I came to Connacht because they sold me a vision about where they wanted to be," he said. "They have backed that up with massive investment in the infrastructure.
"For example, I started off with one assistant coach. Now I have a full complement of four and we have a local chief executive born and bred in Mayo (former Connacht full back Willie Ruane).
"Last year and again this year we've been out among the five counties - Sligo, Roscommon, Leitrim, Mayo, Galway - spreading the word.
"As a result, I've seen a huge growth in interest in the sport all over the province. Heaps of kids at grassroots level are actively involved and it's great to see them wearing the Connacht jersey."
Just as Lam's Irish employers inspired him with their vision, so the head coach sold it on to the province's biggest signing, the 100-cap All Black Mils Muliaina.
"What struck me particularly last season was that we had lots of good young talent, especially in the back line," he added.
"All they lacked was experience, someone who could mentor them. Mils was the first person I thought of, the perfect man for the job who'd been part of the leadership group at the Blues when I was in Auckland.
"I sold him the vision and that vision is to qualify for the European Champions Cup as one of the 20 best teams in Europe. At one stage last season we weren't that far away. This time our aim is to go one better.
"Mils may not have been able to get on the field yet because of the recovery from an elbow operation but his contribution will be massive. He's someone all the boys at Connacht have watched from afar and admired."
The same can be said of another imminent arrival from New Zealand, the Chiefs' highly-rated centre Bundee Aki.
First of all, they have to get into the team, far from a foregone conclusion given the collective heroics in seeing Leinster off the premises on a night when they lost one of their most formidable warriors, John Muldoon, to the bin and still made it.
As befitting a competition of real stature, the GUINNESS PRO12 fixture doesn't get any easier.
No sooner had they beaten the reigning champions than Connacht had begun preparing for a trip to Clydeside and another mighty challenge against last season's beaten Grand Finalists.
Glasgow's Warriors return to Scotstoun for the first time since their last-kick win over Leinster in the opening round after two rewarding trips to eastern sector of the Welsh rugby belt.
Virtually identical results - 33-12 against the Blues in Cardiff and 33-13 against the Dragons at Newport - brought them nine points out of a maximum ten.
In the process, they have made quite a statement - that this time they intend going into the play-offs as number one contenders and the promise of a home run all the way to the trophy.
For now, they dare not look beyond opponents who have conceded just two tries so far this season.
Connacht will not be the least bit overawed at going to a place where Gregor Townsend's largely all-Scottish cast have swept all before them since January, a run which started with a squeaky 8-6 win when Muldoon and his men were last in Glasgow.
As Lam told me on the eve of the season: "There are some big things happening in the west of Ireland."
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