FOR a club eyeing up a return to the Premier League this season, Middlesbrough delivered a Champions League performance. Manchester City could be crowned the best team in Europe come May, yet this was the day they were no match for brilliant Boro.

The whole of Teesside knows there is a promotion priority but, at the home of the reigning champions of English football Middlesbrough made the rest of the country sit up and take notice of Aitor Karanka’s Riverside revolution.

From front to back and left to right, Karanka got his tactics absolutely perfect to stun Manuel Pellegrini, who rightly admitted afterwards that City’s Championship opponents “deserved” to win.

Working out a gameplan to defeat a squad so expensively assembled and dangerous is one thing, implementing those tactics is a different thing entirely. To a man, Middlesbrough’s players succeeded.

While Tomas Mejias, the goalkeeper who has not done much right since his arrival, made save after save to keep Sergio Aguero, James Milner, Stevan Jovetic and Aleksander Kolarov at bay in the first half, the confidence running through the team wearing red just grew and grew after that.

The tightest defence in the Championship frustrated Aguero and Co, while Grant Leadbitter and Adam Clayton constantly tormented the City midfield. The wide-men, both full-backs and wingers, operated in both directions effectively, with goals from Patrick Bamford and Kike securing a place in round five.

And then there was former Peterborough forward Lee Tomlin, by far and away the most exciting performer on a pitch also parading talents such as David Silva, Jesus Navas and Stevan Jovetic. If there were football enthusiasts nationwide unaware of Middlesbrough’s progress under Karanka this season, they know all about it now.

“I don’t have words to explain my feelings after this; it’s amazing,” said an understandably satisfied Karanka. “Sometimes after previous games I have said I have players playing in the Championship who think they are a Champions League player. Here they showed they are Champions League players with this performance.

“I am very proud. It’s the whole squad. I have to enjoy it. I will enjoy this day. For me this is my proudest achievement, it has been very emotional. It has been a really emotional day for me. The biggest I have had here.

“Our crowd, together with the players, it has been special, really special. I felt when the draw was made at Manchester City that our crowd would enjoy it and I’m really pleased that this club has enjoyed this kind of moment again.”

With Middlesbrough high-flying in the Championship, confidence was clearly strong among the players going in to the trip to the Etihad Stadium that a surprise could be sprung. Having earned the right to be goalless at the break, Karanka sensed a unique afternoon was on the cards.

“We won because we deserved it,” said the Spaniard, whose side’s defensive record is only bettered by Southampton in all four divisions this season. “I told them at half-time that Man City were in our hands.

“The only chances they had in the first half were from our mistakes. In the second half we fixed those mistakes. We didn’t lose the ball the same number of times as we did in the first half and we created a lot of chances.

“They trusted themselves to get a result. They were thinking they could beat Man City and when we scored we could have had two or three more. They had one or two but no clear cut chances. It showed how much the players wanted to win this game and how much they believed they could win.”

After Mejias’ impressive first half showing, he hardly had anything to do after the restart as the men in front of him kept the City advances at bay. Even after Bamford had put Middlesbrough ahead seven minutes in to the second half, they still looked comfortable.

The 21-year-old was rewarded for his persistence in chasing down Albert Adomah’s flick beyond goalkeeper Willy Caballero when Fernando, whose weak back pass was to blame for the opener, attempted to clear and hit the forward before going in.

Many teams would have just sat back, parked the bus and attempted to hold on for the rest of the game. Not Middlesbrough, who sensed the best form of defence against the Premier League champions was to keep counter-attacking whenever possible.

Bamford, Jelle Vossen and Adomah all had great chances to extend the lead, while a moment of true brilliance deserved to end in a goal when the dynamic Tomlin’s drag back saw him spin around Vincent Kompany before his effort curled off the inside of the post and rolled to safety.

After Frank Lampard had hit the post at the other end, Middlesbrough were rewarded moments later with the crucial second. The last counter-attack of the afternoon saw Bamford’s neat flick in to the path of substitute Kike taken on and drilled low beyond Caballero.

This was no fluke. Middlesbrough were deserving winners and every member of the team formed an integral part of the triumph. As for Karanka, his stock has risen to new heights and his latest chat with Jose Mourinho will have been an interesting one.

The former Real Madrid assistant boss said: “It’s an important win for me of course it is because I am learning. I have to improve every single day. I will see my family for the weekend but then I will focus on Brentford.

“If we lose on Saturday everything will be bad. I have been in football for 20 years, so it can soon get you down. City away is a great performance, but the club and the performance are the main things, not just one game. Brentford is next.”

And so Karanka’s focus has already switched and there lies his message. Saturday’s FA Cup victory has provided some lasting memories, but facing Manchester City in the Premier League next season remains the main goal.