Manchester City demonstrated substance as well as style as they overcame Liverpool, the greatest threat to their hopes of retaining their Premier League title, on a night of searing tension.
Pep Guardiola's City side - who made history to win the league with 100 points last season - knew they would need to dig deep into their reserves to beat a Liverpool team arriving at Etihad Stadium on the back of a 20-game unbeaten start to the campaign.
The purist flourishes that have become the hallmark of City's style were set to one side for much of a frantic, intense encounter in favour doing the dirty work required to get the job done after Guardiola admitted himself that a failure to win would make their title task close to impossible.
And while the headlines may go to goalscorers Sergio Aguero and Leroy Sane, City's whole approach and their victory was built on the performance of their great unsung hero.
For all the glittering array of riches assembled at City, Fernandinho is the glue that holds all the parts together.
The 33-year-old Brazilian is the man Guardiola misses most when he is absent, whose presence casts an understated influence over games in a such an impressive manner that City have still not found anyone who can do a similar job.
Fernandinho delivered a masterclass here. He was such an all-consuming influence that on some occasions he appeared to have a body double operating in all areas of the pitch.
He was combative but composed, a creator as well as a destroyer. Fernandinho was a man on a mission to deliver the complete midfield display and succeeded spectacularly.
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Fernandinho epitomised a City performance that, unlike many of their others, will not win the usual marks for artistic merit but ticked all the boxes for effort and character.
And it earned them their most vital victory of the season because anything other than three points would have left Liverpool in an even more imposing position than the one they hold.
It was a frenzied affair, which inevitably reduced the style on show, but City and Guardiola will not care about that.
There was a ludicrous suggestion starting to build that Jurgen Klopp's Liverpool, with their recent impressive record of losing only once to City in their past 11 meetings in all competitions, had somehow worked their way into the minds of Guardiola and his players.
Nonsense. And this was a night that proved City, whether they eventually win the title or not, have the mettle of champions.
The scenes at the final whistle spoke of belief restored, of confidence rebuilt after that recent wobble of three losses in four league games, and of the expected consequences of inflicting the first league defeat on a Liverpool team threatening to sweep all before them.
All this after a game played out to a wall of sound that proved the Etihad can generate big-match colour and noise to suit the occasion.
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Guardiola turns cheerleader for battling City
Guardiola was a central player in the drama.
He threatened to boil over - in fact he did boil over - when referee Anthony Taylor waved play on in the second half, reduced to a scarf-throwing, arm-waving figure of fury as he confronted fourth official Martin Atkinson before order was restored after a visit from the man in the middle.
And as an air of panic gripped the stadium, with City falling back and Liverpool being invited to launch a succession of long balls into the area, Guardiola took on the role of cheerleader so often assumed by Klopp - demanding greater noise from the stands to see City over the line.
Guardiola lavished praise on his players and it was merited. City needed a real show of resolve to get maximum points after Roberto Firmino's equaliser threatened the return of old demons that have undermined them in the past against Liverpool.
There was an audible dip in the atmosphere as Liverpool, for a few minutes at least, gained the sort of impetus that saw them overturn a similar deficit to win 2-1 in the Champions League quarter-final second leg here last season to secure a 5-1 aggregate win.
City and their fans could have been forgiven for fearing history would repeat itself as Liverpool scented blood but a measure of composure was retained as Raheem Sterling set up Sane for the decisive blow.
There is still a frailty about this City side that induces nervousness both in themselves and their fans, especially the pinball that followed Sadio Mane striking a post in the first half.
And it was all hands to the pump as Liverpool pressed in those chaotic closing moments, although City did not help their own cause with some wayward late finishing.
The hosts survived that frenzied phase - as they needed to do because another Liverpool leveller at that stage would have represented a devastating blow.
The celebrations on and off the pitch were measure of the significance of City's win. This could have been the night when, to all intents and purposes, their pursuit of a second successive title could have ended.
Instead, City and Guardiola can move forward with renewed conviction, bolstered by the knowledge Liverpool made a 20-game unbeaten start to the season and are still only four points ahead of them.
The Reds are in a commanding position but this Premier League title battle has a long way to run.