Two quickfire goals from Dejan Kulusevski and Emerson Royal at the end of the first half put Tottenham Hotspur in the driving seat at the break.
But Pep Guardiola’s men produced an attacking second half to fight back.
Goals from Julian Alvarez, Erling Haaland and a double from Riyad Mahrez resulted in a 4-2 victory under the lights at the Etihad.
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And speaking with mancity.com in his post-match interview, Grealish was quick to emphasise the importance of the win.
“It was massive, it was absolutely massive,” the England international exclaimed.
“To get the win and get the three points, it’s a brilliant dressing room in there now and there’s no time to waste now, we’ll be back in tomorrow and then Saturday, ready for the game on Sunday.”
Despite the first-half scoreline, Grealish thought City were a touch unlucky in the final third during that opening 45.
“I think we had the better opportunities in the first half, but sometimes it’s about luck,” he stated.
“Riyad’s first goal in the second half was a deflection, so you need a bit of luck sometimes and we certainly had that in the second half.”
City’s No.10 also took the time to applaud the fans for their support in the second half.
“Brilliant, honestly, it was outstanding, I’ve really found it good in the second half especially,” he said.
“I think certain games stick out at the Etihad and that was definitely one of them, so more nights like this, I hope.”