Pep Guardiola credited a tactical change at half-time with opening up Sheffield United to help Manchester City end 2019 with three points.
The Catalan had seen his side struggle to create against the Premier League newcomers and they were goalless at the break but it took just seven minutes for them to take the lead in the second half - albeit with a goal that upset the visitors after the referee got in the way of the ball.
City moved up to press Sheffield United further up the pitch, bringing Sergio Aguero into the game more and pushing their XI forwards with Kyle Walker and Aleks Zinchenko getting more involved in attacks.
With the midfielders more able to influence the game, Kevin De Bruyne laid on the first goal and then exchanged passes with Riyad Mahrez to wrap it up in the final 10 minutes.
"I understand why Sheffield United are in the position they are in in the table and why they didn't lose one game away so far," said Guardiola.
"They had incredible physicality and we had less than 48 hours to recover so the first half we had problems to attack them. We changed something in the second half and were much, much better.
"We put more players close to Sergio and the guys who passed the ball outside inside are players with better quality than we had in the first half with Kevin and Bernardo [Silva] and after [Ilkay] Gundogan. That was the reason why. We attacked in the first half with wingers and in the second half with full-backs."
