If Igor Tudor believed his brief losing reign could not get any worse after the home defeat by Crystal Palace, he reckoned without one of the most humiliating nights in Spurs' recent history.
The Croatian was bold with his team selection, especially dropping regular first choice Guglielmo Vicario for young deputy Antonin Kinsky.
To say it was a move that back-fired is a masterpiece of under-statement as Kinsky suffered the sort of personal nightmare that will take huge strength of character to recover from.
Even the hearts of Atletico's passionate, partisan support went out to Kinsky as his number came up following his errors, with team-mates also moving to offer words of comfort as he went off.
Tudor was in optimistic mood before the game, but that all changed inside 23 madcap minutes as Spurs slipped â literally â from one costly error to another, effectively ending this contest and, in all likelihood, the tie.
Spurs actually created chances of their own as Atletico stepped off the gas, but the damage was already done.
And it may be permanent damage for the beleaguered Tudor, who arrived as an emergency measure with a reputation for having an instant impact in his chequered coaching career.
Instead, things have arguably got worse and now, with a testing trip to Liverpool on Sunday and Spurs just one point off the Premier League relegation places, the club's hierarchy look like they will soon face another decision of huge significance in a bid to somehow rescue a season in freefall.