In congratulating new Premier League champions Manchester City, Sir Alex Ferguson reminded them that they have a long way to go before they can be considered Manchester United's equals. The United manager could not resist comparing his club's reputation as serial winners with City, who have lifted the title for the first time in 44 years. While Ferguson grudgingly acknowledged City had legitimate cause for celebration, he insisted the blue half of Manchester still had plenty to do before they could rival United's history. "They can go on as much as they like - that's what you would expect - but the history of our club stands us aside," Ferguson said. "We don't need to worry about that. I think we have a rich history, better than anyone and it'll take them a century to get to our level of history."Even at 70, Ferguson is determined to be the man who tries to halt City's attempt to repeat their success next season. "We accept challenges. We are good at that," said Ferguson, after a 1-0 win at Sunderland on Sunday did not prove enough to claim top spot. But he was gracious in his praise of City's achievement, saying: "On behalf of Manchester United, I would like to say congratulations to our neighbours. "It's a fantastic achievement. This is not an easy league. It's the hardest league in the world, and anybody that wins it deserves it. "At the start of the season, if I remember correctly, I said 82 points would probably win the league this season and we are seven points ahead of that. But look, it doesn't matter, we've lost the league. "It is a cruel way to have the title ripped away, but I've had a lot of ups and downs in my 25 years here. There will be times when we can sit back and say we did this wrong, we did that wrong, but 89 points would have won the league most seasons." Wayne Rooney scored United's goal at Sunderland and, with City trailing to Queens Park Rangers, they believed they had won at the final whistle. Thirteen seconds later, City scored their winner and the championship had crossed the city. Ferguson said: "All we had to do was concentrate on our job and that's what we did, but you are going to get certain types of reaction from the crowd. "We knew five minutes' extra time was being played at City. Our game had three minutes' stoppage time and you don't know what can happen in the extra two minutes, but they got that break and won the game. "We should take credit because of the fact we had so many injuries and coped with them very well. We have some young players and they have now experienced what happened here today. Hopefully in seven or eight years they will be at Manchester United and the experience is good for them - even if it's a bad one. "They're a good bunch of lads. The younger players will remember today because sometimes a bad experience is even better for you. When you've got a certain character and a good purpose about you, then you shouldn't fear the future and I don't think these lads will." Sunderland manager Martin O'Neill said: "The last couple of minutes of the game have taken me back a few years to the season at Celtic when we lost out on goal difference. It's the most harrowing thought you can have. "Wayne Rooney was playing the ball in the corner near the end and thinking they had won the game, so to hear the news coming through was unbelievable. "Sir Alex might be coming into my room for a moment and I've got to say I'm dreading going in. He will be bitterly disappointed because this would have been a sensational year for him to win the championship. "He's got so many titles that he's lost count, but he will be so disappointed about this one." O'Shea injury fears Sunderland's Irish international defender John O'Shea is in danger of missing the UEFA EURO 2012 after suffering a recurrence of a calf injury before half-time against United. O'Neill admitted he feared O'Shea could lose his place in Giovanni Trapattoni's squad, which meets next Sunday. O'Neill said: "As he came off, that was my thought. I thought it might be a concern. He didn't feel comfortable. He started to feel his injury and didn't feel confident about moving on it. I haven't checked with the physio, though, and may be jumping the gun."