In the summer of 2009, when Jose Mourinho was preparing to embark on his most recent Champions League title-winning season with Inter Milan, a small village football club outside Leipzig were acquired by a major drinks manufacturer and embarked on a campaign of their own in the fifth tier of German football.
A decade is a long time in football, when reputations can be made or lost, and so it must have felt for the current Spurs manager as he spent 90-plus helpless minutes on the touchline watching his Champions League season being crushed.
For Mourinho, 10 years on since his second title in this competition, this was a defeat without honour, a round-of-16 whimper, the kind of which he would have once been contemptuous of in other clubs.
It was decided early, with two goals in 21 minutes from the RB Leipzig midfielder Marcel Sabitzer in this, the 10th season of one of the most remarkable rises in the history of modern European football, at the club funded by the energy drink empire, Red Bull.
Their marquee club is now in the last eight in Europe's premier competition, which is some achievement given that the original timescale for the transformation of the humble village side of SSV Markranstadt into a Bundesliga force was eight years.
RB Leipzig march on, and Spurs progress to who knows where. They are without a win in six games now, including an FA Cup exit on penalties to Norwich City and, having talked down their prospects all week, Mourinho got a performance that he could not have been surprised at.
His goalkeeper Hugo Lloris looked vulnerable, but anyone might have done playing behind a defence as exposed as this one, behind a predictably ineffective attack.
The substitute Emil Forsberg, on for Sabitzer with seven regulation minutes remaining, added the third.
Last season's finalists may well be labouring under the season's biggest injury crisis, but they were flat and uninspired. For Julian Nagelsmann, the 32-year-old RB Leipzig manager, this was another slick performance that will have made his Premier League admirers take note.
The worst kind of start for Spurs, and for Mourinho exactly the kind of sloppy approach that undermines a manager on a night when the circumstances dictate that everything must be right. He had wandered over to Nagelsmann when the RB Leipzig coach watched the warm-up with his assistants and there were friendly, coronavirus-safe elbow-bump greetings.
Within 10 minutes of the game played, Spurs were exposed down their right side and not for the last time. Leipzig's players are a well-disciplined, sharp bunch, with the kind of confidence one might expect of this upwardly mobile club. The Spurs side they were up against felt further than ever from the team who could rescue any situation up to last season's Champions League final.
It was there in the poor quality of the performances from Serge Aurier, who was caught out for both opening goals. The Germany international Timo Werner, recycling the ball after his initial shot had been blocked by Eric Dier, picked out the run of the Sabitzer arriving at just the right time to ping a shot into the corner.
Flapped It was not so well-aimed as to be unsaveable, but Lloris flapped an uncertain right hand at the ball and through it went, one more mistake from a man who was once a great keeper. He was to do the same for Sabitzer's second, when a pass out to the left wing-back Angelino, on loan from Manchester City, dropped over the head of Aurier.
From the cross the Austria international Sabitzer stole in to direct his header inside the near post.
Barely 20 minutes had been played. Mourinho was twitchy at the prospect of a Champions League humiliation. As he considered his options there was no shock-tactic substitution open to him.
Giovani Lo Celso produced the first shot on target for the away team, with around four minutes of the half remaining.
There was very little that Spurs could offer in response after the break and, when Forsberg pounced on the loose ball to score in the closing stages, it felt like a fair reflection of the game that the margin of victory should be so great.
Spurs had managed just three shots on target throughout the evening.
There was a debut for the Spurs teenager Malachi Fagan-Walcott in injury time, one day before he celebrates his 18th birthday, although there will be precious little celebration in his club.
They have been well beaten and the rest of the season, starting with buoyant Manchester United on Sunday, is just the game that Mourinho did not need. (© Daily Telegraph, London)