The destination of the league title may now effectively be confirmed but the rest of the Champions League chase has never been so uncertain or exhilarating.
Indeed, it wasn't just this game at White Hart Lane that was transformed in a scintillating seven-minute spell but also the entire tone of the race.
One of the most remarkable aspects of this performance, in fact, was that Spurs hadn't suggested anything like it for the last six weeks - let alone the first 75 minutes of this game.
Prior to Clint Dempsey's equaliser, they had been lacking both spark and any semblance of energy. The toll of an intense season on an inexperienced, small squad seemed to be having a terminal effect. The flatness of the first half, in particular, was only a continuation from the dismal last few weeks and was perfectly illustrated by the manner in which Carlos Tevez so easily dispossessed the Spurs defence, got round them and set up Samir Nasri's opener.
It was certainly a far cry from the period of the season when there was considerable debate about who was responsible for Tottenham's progress and the sensational scoring of their most high-profile player: Andre Villas-Boas, Gareth Bale himself or, even - in some especially fanciful quarters - Harry Redknapp.
The ending to this game, however, encapsulated the importance of both. Villas-Boas's tactical changes altered the game, and Bale's brilliance transformed it.
The extra space from a double-switch in midfield and the introduction of Jermain Defoe's running allowed the winger the space to provide such an exquisite pass for Dempsey to prod home. With the outside of his boot, Bale completely inverted the game and the race.
And, for all that Defoe proceeded to power Tottenham into the lead and the Welsh winger himself emphasised the sweeping nature of the comeback with his fine clincher, Villas-Boas cited the nature of that opening goal as key to the game.
"I think, when we managed to score the first was the key to the game," he said. "You gain the momentum, the confidence. Emotionally, the stadium also helps. The fans were outstanding.
"So, probably, the equaliser was the decisive moment. Emotionally, after it, we were hyped up."
The key question, now, is whether that will be the case for the remainder of the season. Certainly, Spurs will not again have the Europa League schedule that so eroded their energy. Moreover, the psychological effect of an ending like this - as Villas-Boas implied - may well actually override any sense of fatigue after that trying last four weeks.
This is not to say Spurs don't have problems. Emmanuel Adebayor's complete lack of influence almost rendered fatal their failure to sign another forward in the January window.
Similarly, they lack bodies in midfield. It is testament to Villas-Boas's tactical intelligence, rather than Tottenham's options, that he was still able to work out a way to eventually outmanoeuvre City.
"I think in the second-half, the team found its rhythm, more space, better passing," the Portuguese said. "We managed to find channels more easily and we created a lot from that."
They do need to find extra options but, for the moment, the brilliance of Bale and sophistication of Villas-Boas should be enough to successfully navigate the final four games. At the very least, it's in their hands.
It is, of course, a long time since City had the league title in their hands. And, after this result, it is now effectively certain that Manchester United will lift their 20th over the next week.
To a degree, though, Tottenham's success in this game was only accentuated by Mancini's failure.
Of course, City could easily have scored a second before Spurs' first and it was always going to be somewhat inevitable that a team with just pride to play for was going to be less urgent than one with a proper target.
"I can't say nothing bad about the performance because I am happy about it," Mancini said. "For nearly 80 minutes we played well but, when you play like this, you need to score two or three goals.
"We had the game under control. Tottenham were trying to win because it was important for them but I think we lost the game through our own fault."
That frankness was admirable because, in truth, City's response was anything but. By contrast, it was meek and uninspiring. It was already into the stoppage time when, with his team well behind, the Italian decided to bring on - of all people, and with Sergio Aguero on the bench - Joleon Lescott.
The only explanation could surely have been that he was going to switch to three at the back and reshape the side to counter Villas-Boas's changes. Instead, the defender went straight up front.
It was a ham-fisted response in keeping with City's entire title defence. Just as they effectively surrendered to circumstances in this match, they did the same in the season as a whole.
Although Mancini should have enhanced the mental effect of last season's magnificent title win with superior signings or just allowing the team to flow, he only complicated affairs.
Spurs, however, have greatly complicated the race for the top four - and it is all the more compelling as a result.