Sir Alex believes the tense 1-0 victory over Fulham was a \"great game\" for the champions because it will act as a warning for the remainder of the run-in. The Reds will face similar battles against determined opponents in the weeks to come and, despite the experience of the side, a wake-up call could prove useful with the three points safely banked. After moving three points clear at the Barclays Premier League summit, the manager was happy to take the positives from a difficult evening. \"The matches are all challenges,\" he told Sky Sports. \"That\'s a great indication. It was a great game for us tonight because that\'s exactly what it\'s going to be like for the rest of the season. Teams are going to be battling and fighting, trying to survive, and not be lambs to the slaughter to Manchester United because they don\'t want to be seen to be laying down. \"Fulham put in a massive effort tonight. They\'re a very experienced team and were very difficult to break down. When you sit back, it doesn\'t matter if you\'ve got 11 plumbers, joiners or footballers, it\'s hard to break down. We did enough to finish the game off but didn\'t do it and nearly paid the penalty.\" Penalty was a word on everybody of a Fulham persuasion\'s lips after Danny Murphy was sent tumbling inside the box in the closing stages by Michael Carrick. Referee Michael Oliver failed to point to the spot and Sir Alex felt another clear shout in the first half, for the hosts, may have been playing on the official\'s mind. \"I think they had a claim,\" added the boss. \"No doubt. \"I think we had a claim for clear handball in the first half, maybe it was close to the attacker but it was a claim and Patrice Evra thought it was stonewall as he handled the ball going into the penalty box and denied an opportunity. \"Maybe the referee was thinking about that, certainly Carrick caught Murphy\'s heel as he\'s come back. But we deserved that [fortune] because we completely dominated the game until the last 15 minutes.\" Sir Alex felt his team were a little tired, despite having a blank week, but felt three players performed particularly well in helping to get the important victory. \"It\'s the result for us tonight and the three points is what we\'re after,\" he added. \"I thought, for an hour, we played very well. The passing was quick, decisive and we made some decent opportunities but credit to Fulham. \"It was a determined defensive performance by them. The problem is when you play teams who sit in their half all game, they\'ve always got something left and they had more than we had in the last 15 minutes. A little bit of tiredness came into our game and we started giving the ball away. They capitalised on that and had a lot of counter-attacks through it. \"Antonio Valencia and Jonny Evans were our best players. Rafael did very, very well also. I think a player like Valencia has got exceptional talent. Some people actually under-rate him. We don\'t. That\'s why we bought him. When he\'s back and in that form, he gives us a big chance.\" The manager explained that Rio Ferdinand\'s injury should not prove too serious, after he was substituted despite the match being precariously balanced towards the end. \"Rio got a bit of stiffness,\" said Sir Alex. \"He gets that, you know, from time to time, the stiffness in his back. So we brought on Chris Smalling as a safeguard. \"If Rio had played it out, he would probably have managed it okay but then not be available for a couple of weeks so I think we\'ve done the right thing at the right time.\"