It might have been easy for Tottenham and Mauricio Pochettino to throw in the towel.
They were three games into their Champions League campaign this season and they were dead and buried. A pair of defeats – to Barcelona and Inter – plus a disappointing draw with Dutch also-rans PSV meant they had gained only one point by the turn.
It’s happened before – not least with Brendan Rodgers’ Liverpool – that clubs have decided to run up the white flag and end their quest for European glory.
There are other priorities these days – league games, preservation of fitness, the top four, the very Premier League title itself – and some managers would consider what was left in front of Spurs as three dead rubbers.
But where there’s a will there’s a way.
The subsequent wins against PSV and Inter – here at Wembley – gave them everything to play for in the final group stage game away at Barcelona.
They had the opportunity to follow Lionel Messi and Co. into the knockout rounds. There, anything could happen.
It’s hard to know now what the odds of Spurs being Champions League quarter-finalists were the moment that Luuk de Jong equalised for PSV in the 87th minute on matchday three.
For sure, it would have been a lot more unlikely than it is right now, after Wednesday's remarkable 3-0 last-16 first-leg win over Borussia Dortmund.
Spurs have forged their own path here the hard way.
This week we’ve seen a Paris Saint-Germain team deal with the absence of two key attackers in Edinson Cavani and Neymar with the minimum of fuss.
It’s no exaggeration to say Spurs did the same and – arguably – against a team of better quality than Manchester United too.
Harry Kane is their captain, top scorer and all-round totem. Dele Alli is creator-in-chief. They were without them both against Dortmund and what did it matter?
The Bundesliga leaders have problems of their own, given Paco Alcacer, Marco Reus and Manuel Akanji were unavailable for the trip to London.
The Germans – who lost the 2013 Champions League final on this ground – have also seen their season’s momentum judder to a halt in recent weeks.
They have not won a game since the last week of January, have tumbled out of the German Cup and came into this game in much worse shape than they were when the draw was made.
But there is quality in their ranks – not least in Jadon Sancho, Christian Pulisic and Axel Witsel – and had to be dealt with.
Spurs themselves had had double cup exits to contend with and a defeat at home to a top-four rival. The manner, however, in which they stick to their guns is admirable and their rewards are coming.
This was cagey and Spurs didn’t want to give anything away. They deployed Jan Vertonghen in place of the injured Ben Davies on the left side of the defence in the expectation he would deal with the threat of Sancho.
There were times in the first half when he let the Englishman slip and mischief was made on that side. But Spurs saw it all off.
And Vertonghen delivered a inch-perfect assist, and a very tidy and very important goal of his own.
It was Son Heung-min who was selected to start in the central attacking role with no Kane available. His turn prior to Vertonghen’s pass for the opening goal had Dan-Axel Zagadou chasing his tail. The finish looked easy and was anything but.
Son is a player Pochettino loves. And it’s not hard to see why. He has kept Spurs in the hunt not only for the top four but the title itself in recent weeks thanks to goals in very tight games. And here he separated two teams, neither of whom started with a genuine centre forward.
The late Spurs swell – combined with that vital clean sheet – has all but seen them through.
Serge Aurier is much-criticised around these parts but no player in the world could have delivered a better assist for Vertonghen's header, while Fernando Llorente popped up at the end with yet another important goal.
While other teams look for and find excuses – players not fit enough, players not fitting the philosophy, managers playing players out of position – Pochettino and Spurs have rolled their sleeves up and got on with the job.
A thin squad, no transfers since two windows ago, without key men and for the time being homeless, and up against Sancho and Pulisic – nothing fazes this Tottenham team.
Sometimes you just have to take your hat off and salute a job well done.