This was not the greatest Manchester City performance of the season - in fact they would struggle to do worse - but it was certainly a great result in the circumstances.
City have already gone to three of the Premier League's most threatening sides and come away with seven points. They were intelligent in dismantling Unai Emery's fledgling Arsenal team on the opening weekend and nullfying the supposedly kryptonic Liverpool at Anfield, yet at Wembley they dug in and fought after almost everything else failed.
It looked like the terrible pitch, ravaged by boxing and NFL clashes in previous weeks, and forced into service because Tottenham served up an even bigger shambles elsewhere in London, would have little effect on City when they took the lead with one of their trademark goals after just six minutes.
Kieran Trippier's misjudgement allowed Raheem Sterling in behind, and the England winger did brilliantly to drive to the byline and cut back for Riyad Mahrez, who proved he is learning his new duties by being in the right place to fire in from close-range.
City almost doubled the lead straight after that and it had looked as though they could run away with it, but the longer the game went on the more unsure of themselves they looked.
Spurs were no better, their own creative talents and smart defenders thrown off kilter by the shambolic surface.
It is normally a pleasure watching Pep Guardiola's City play but this was a game to be endured rather than enjoyed.
The pitch, with it's many dry, bare patches and various divets, ensured neither side could do the basics right, and it seems that when City cannot do the basics they increasingly find they can do nothing at all.
Guardiola's City is built on rhythm and structure, he strives to control every detail of a football match, no matter how minute, and after sweeping to the title last season, and starting their defence brilliantly this, it is almost certain that his players are acustomed to the same level of assuredness.
So here, the less control they could exert, the more uncertain they became.
Their full-backs, in particular, were regularly atrocious. It is accepted that Benjamin Mendy has one dodgy moment in him per game but here he had about 15, and Kyle Walker wasn't much better.
City still found ways of finding space in the middle of the pitch, the kind of spaces that are usually enough to exploit and kill off the opposition, but they could not do it.
At first the passes went astray, but by the end they were barely even being attempted, City's players second-guessing themselves in a way they have not done since Guardiola first bowled into the club and retaught most of them how to play the game.
The game had already descended into obvious farce by the time Kevin De Bruyne entered the fray after 71 minutes, but he was the litmus test for how poor a spectacle this was; the mercurial Belgian may be suffering a bit of rustiness after two months on the sidelines but the fact he was tackled in his own box and then misjduged two through balls tells you that this was no usual night.
Unable to kill off their opponents, City just stopped trying. In the final third they tried to hold on to the ball for too long, only to lose it. Spurs could have nicked an equaliser, but of course they were playing on the same pitch. Mahrez's radar was clearly on the blink as he began running back towards his own half, only to meekly surrender the ball under pressure and allow the hosts their best chance of the night.
Erik Lamela was presented with the golden opportunity but he could only fire over with the goal at his mercy, the home fans this time lamenting the state of the Wembley turf.
In the end Guardiola threw on Vincent Kompany in the place of David Silva, who himself had been shoved up front, to help see the game out. The hapless Walker gifted his former employers a soft 95th minute corner, but it was Kompany who headed it away to safeguard the victory for his team.
Kompany did his bit but Aymeric Laporte, John Stones and Fernandinho were City's best players. It was that kind of night.