Yaya Touré was Manchester City’s buccaneering force when Roberto Mancini’s side ended a 35-year trophy drought by beating Stoke City 1-0 in the 2011 FA Cup final, claiming the first silverware of Sheikh Mansour’s proprietorship.

The Ivorian scored the winner at Wembley, as he had done in the semi-final defeat of Manchester United which marked the moment City began to dislodge their neighbours as England’s dominant force. Touré, too, was in the XI that handed United a 6-1 hiding six months later at Old Trafford which continued an ascendancy that, 12 years on, has them seeking to beat United again at Wembley. This time in Saturday’s FA Cup final, the second step of the attempt by Pep Guardiola’s gilded team to landi the treble and emulate Sir Alex Ferguson’s 1999 vintage.

Touré joined from Guardiola’s Barcelona for £24m in summer 2010, arriving as a two-time La Liga champion and treble winner with the Catalan club. “As soon as I signed and came into City my head was about trying to change things and make things happen – try to help with that positive mentality, that winning mentality on the pitch, and my professionalism and desire to achieve,” he says.

“In that period United were so comfortable – they’d win week in, week out, they were winning the league easily and on top of us were all these other teams like Chelsea, Arsenal. So when you come into a new environment where the league is competitive like that, what you have to do is work hard, improve and try to do better than them.

“Winning that first trophy was important. The players understood why I was coming and could see the hard work I put in. It was totally tireless, to be honest with you. It was game after game. I wanted to set the bar high. I wanted them to see my commitment, my desire.”

A teammate was Patrick Vieira, who had captained Arsenal to their invincible league campaign of 2003-04. Mancini gave the Frenchman the dressing-room floor as City prepared to walk out to face United at Wembley on 16 April 2011.

Touré says: “He was one of the most important players we had in terms of experience, winning mentality. He delivered a great speech. I couldn’t tell you precisely what but we all remember the message: ‘Yes, we’re going out to compete against one of the top teams but it’s one game, we don’t have to shy – if we win we’re through but be sure to remember the hard work we’d done to get there and that we compete and show maybe the balance [between City and United] is going to change.’”

Touré’s decisive blow came by pickpocketing Michael Carrick near Edwin van der Sar’s goal. “When I jumped on him I knew he didn’t see me coming,” he says. “I anticipated the moment, won the ball, and then only had to push it past [Nemanja] Vidic. Van der Sar came out – he’s big – but I knew I had to put the ball between his legs.

“We celebrated more than actually winning the final. Even on the train back we were still celebrating. It was a mark of the change that was happening. The executives were on the train with us, they came into the dressing room to share our happiness. They were feeling like: ‘This is it now, change is coming now at Man City.’ The fans realised it as well. Everyone around the city started to realise it. I remember when I went to the shops or supermarkets and even United fans would say: ‘Oh Yaya, you guys, jeez.’”

The finish against United was with Touré’s right foot, the following month’s Wembley winner came with the left, and at the final whistle the new era had liftoff. The next even more significant marker of the power shift came in the derby eight matches into the 2011-12 season. City, in first place, travelled across town to take on United, who were second.

“What hurt United the most – the club, their fans – was the 6-1 win,” says Touré, now a Tottenham youth coach. “That was impressive from us. After the FA Cup, we believed we could beat them even at Old Trafford with Ferguson – one of the great managers. Old Trafford is the most emblematic stadium around the world.

“It was like a slap in the face of United fans, even players in front of Ferguson. I remember watching highlights of the game and you could see the camera on Ferguson’s face and it was red. He didn’t say anything. You could see it in his eyes. He was like: ‘Oh.’ It was incredible.

“We played much better than we did in the FA Cup – we won that game 1-0 but we got dominated in the first half. The one chance we got we scored and then they got a red card [Paul Scholes] and we took advantage. But at Old Trafford the 6-1 was different. It was in their stadium, against the best manager in the world who had made their team great and we battered them 6-1. What’s better than that?”

City claiming a treble, matching the United feat and downing them in the Cup final along the way, may just trump it.