Pep Guardiola was clear that Kevin De Bruyne alone would not solve Manchester City’s problems, but there is little doubting the difference the Belgian makes when he is fit and firing.

De Bruyne’s long-awaited return to the starting XI was just the shot in the arm the ailing Premier League champions needed on a night when they rediscovered a ­little of their old swagger to end a seven-match winless streak, claim a first clean sheet for six weeks, and disperse some of the storm clouds in the process.

Things may not have turned out quite so well for De Bruyne and City had a sloppy misplaced pass from the midfielder been capitalised on by Chris Wood on the half-hour mark. With nine league goals to his name already this season, the New Zealand striker looked certain to draw Nottingham Forest level and cancel out Bernardo Silva’s early finish as he galloped through on goal.

But Wood dragged his shot wide and De Bruyne would make the most of his reprieve just a minute later when he lashed home a bullet of a shot into the top corner after finding himself in acres of space in the penalty area. On such moments can games – and maybe even seasons – turn.

Guardiola will certainly hope he can keep De Bruyne fit and available for the foreseeable future. Now 33, the midfielder may be past his prime. But he can still bend a game to his will when the moods takes him, and Forest were on the wrong end of what felt like De Bruyne unloading weeks, months even, of pent-up frustration.

Gary Neville and Jamie Carragher had hinted at a rift between Guardiola and De Bruyne in the wake of City’s 2-0 defeat at Liverpool on Sunday after the player had been limited to five appearances from the substitutes’ bench over the past month.

But the reality is De Bruyne’s injury problems have required careful management.

“I’m so happy for him, he played 75 fantastic minutes,” Guardiola said, before adding that he would have to see how De Bruyne recovers before deciding if he can start at Crystal Palace on Saturday.

The only downside for Guardiola was another hamstring injury for Nathan Ake that the manager admitted “doesn’t look good”, and a problem for Manuel Akanji, who is likely to miss the trip to south London in three days’ time.

By the time De Bruyne left the pitch in the 74th minute to familiar chants of “Oh Kevin De Bruyne” with City 3-0 up, Guardiola’s mind might briefly have been catapulted to when his side blew such a lead against Feyenoord in the Champions League recently. But, while not completely free of anxious moments, this was still their most purposeful and cohesive performance since a 5-0 trouncing of Sparta Prague on October 23 and it was not just De Bruyne who was responsible for that.

Guardiola had issued a call to arms to the likes of Jeremy Doku, Bernardo and Jack Grealish to start delivering more and the manager will be pleased all three heeded his words. Bernardo and Doku both got on the scoresheet while Grealish, who has often looked exiled on the wing, revelled in a central midfield role similar to one he has played for England under Lee Carsley. It was a welcome change to see Grealish constantly demanding the ball and driving with it from central positions and speeding up and slowing down City’s play. There was also some excellent defensive work, not least a stunning block to deny Alex Moreno.

Given a rousing reception when replaced late on, Grealish has given Guardiola encouragement to continue the experiment at Palace. “Jack has that pace, when to accelerate, how to make more control, he played really good,” the Man City manager said. “I know his quality, he can even play as a holding midfielder.”

Bernardo, too, appeared re-energised against Forest, welcoming the return of De Bruyne, with whom he dovetailed so well, and a fine goal will do Doku’s confidence the world of good. Released down the left by Erling Haaland, the Belgium winger darted inside Nikola Milenkovic before letting rip with a thumping drive as the ball flew into the far side of the net.

Haaland did not get on the scoresheet but was more involved in the build-up play and Josko Gvardiol also gave City an added attacking dimension and could easily have scored twice in the first half. Nominally playing at left-back, the Croatian frequently took up positions you would normally expect of a No 10.

Still, this was not an entirely stress-free night for Guardiola, who admitted City made life difficult for themselves by turning over the ball and inviting transitions. He looked ready to explode at one point late in the first period when Haaland twice lost possession and he must have had a knot in the pit of his stomach when that stray pass from De Bruyne behind Ruben Dias sent Wood away.

Similarly, when Ilkay Gundogan was muscled off the ball moments after De Bruyne had taken his leave and Anthony Elanga fired narrowly over, the Catalan struggled to hide his emotions. Stefan Ortega, preferred in goal to Ederson again, was also forced to make a fine first-half save from Morgan Gibbs-White.

Nuno Espirito Santo, the Forest manager, rued that Wood miss. “It doesn’t reflect the whole game, but that minute is very important for sure,” he said. But while they had their moments in attack, they gave City too much time and space and made too many mistakes. City had taken the lead when Gundogan reached the byline after Forest had been unpicked far too easily and stood up a cross that De Bruyne met with a powerful header. Bernardo turned home the ball on the goal line.

After a run of four successive league defeats – and seven games without a victory – City have rediscovered the lost art of winning. Guardiola will hope it is the start of a marked upturn in form. De Bruyne’s return will only boost the chances of that.