The irony was lost on no one who watched agog on Tuesday night as Rangers, until recently the wounded giant of Scottish football, clinically destroyed Lyons, a French football institution held up as the exemplar of the way a modern football club should be run.

The random fates of two men were on everyone’s lips as Rangers swaggered to their 3-0 win in Stade Gerland. First, Paul Le Guen, until recently the golden boy of French coaches, who established his gleaming credentials at Lyons before coming to Rangers and suffering ignominy. And secondly, Walter Smith, Le Guen’s successor at Ibrox since January and a football manager who has known himself what it is to be pilloried.

What must Le Guen have been thinking while watching this amazing Rangers performance? The Frenchman, the author of the modern phenomenon called Olympique Lyonnais after leading them to three successive Ligue 1 titles between 2002 and 2005, mysteriously walked away from that club before being appointed the new Rangers manager in 2006 amid fits of hysteria in the Scottish sports pages.

It is hard, looking back, to overstate the messianic status given to Le Guen as he took up residence in Glasgow 15 months ago. The truth is, news of the Second Coming couldn’t have triggered more fevered media salivating in Scotland. Le Guen was said to be about to transform Rangers and make them Britain’s very own Lyons.

It was a disaster. Come January of this year, Le Guen was broken, embattled by conflicts of culture and other issues. Enter Smith, the former Rangers manager between 1991 and 1998, who had quietly slipped away from the club via a side-door in his final season after the sort of trophyless campaign that is a blasphemy for either of the Old Firm.

The mystery is this: it has taken a wise old hand, not a poster-boy of the modern European game, to make Rangers a force again. Nor is Smith’s new team merely revived in Scotland, but is a canny, calculating side in these early foothills of the Champions League.

Over a dizzying summer Smith bought ten new players, and three of them – Lee McCulloch, Daniel Cousin and DaMarcus Beasley – scored the goals in Stade Gerland. You only need to consider these three unsung names to understand the ongoing complexity of being a Rangers or Celtic manager: while in charge of one of the biggest clubs in Europe you are left to grope around with an extremely modest budget.

Yesterday, Smith highlighted the feats of Rangers so far in Europe in the context of his own modest expectations for his team.

“I don’t think anyone ever imagined we would start the section with six points, but we’ve got them,” he said, referring to Rangers’ two opening wins in group E against VfB Stuttgart and now Lyons. “In fact, I worried that the section would be so strong that it might dent our confidence by playing in it.

“I don’t mean that we wouldn’t have picked up any points but I was still concerned. When I took over again at Rangers they were third in the league, they had lost in the CIS Cup to a first division team [St Johnstone] and had been knocked out of the Scottish Cup to a side that was relegated [Dunfermline Athletic]. I had to make a lot of changes and you cannot really imagine you are going to reach the Champions League and win two games against the title-holders from France and Germany.

“I’m not being modest – I just think we are punching above our weight. We’ve got Barcelona next and I’m under no illusions, it is still going to be tight. We were just looking to be competitive in the group and I had no great illusions about qualifying from it. But at least now we know we can be competitive.”

It is fascinating being around Smith, a man who, in different phases of his career, has known the kind of opprobrium that Le Guen abruptly suffered in Glasgow.

Before this current European campaign, Smith’s Champions League record was woeful – just three wins in 18 matches stretching back to 1992 with Rangers – and there had been a time in Scotland when he had been dismissed as tactically illiterate on the European stage.

Such damning estimations are always enjoyably quoted yet scarcely examined. In his first spell at Rangers, when it was suddenly in vogue to tire of Smith’s presence and cite other, allegedly brighter young managers coming along, I always remember Craig Brown, then the Scotland manager saying to me: “All you guys in the media mention these coaches or managers – none of them is fit to lace Walter Smith’s boots in terms of knowledge or understanding of football.”

With Everton, then with Scotland, and now by a twist of fate back at Rangers, Smith’s wisdom in adversity is proving Brown correct.