Arsenal hero Thierry Henry insists they are not out of the title race after his sensational last-gasp winner helped them to beat leaders Manchester United 2-1.Henry's header left them 12 points adrift of United at the top of the Barclays Premiership but the Arsenal captain believes it is not impossible to catch them. However, Arsenal's victory was soured by Robin van Persie's broken metatarsal and Henry admits his loss will be a `massive blow' to Arsene Wenger's side. The Dutchman is likely to be out for six weeks at least and his injury took some of the gloss off a fantastic fightback by Arsenal. Van Persie's equaliser cancelled out Wayne Rooney's opener and Henry gave Wenger's side a superb victory with a headed goal in the dying seconds. But Henry said: 'Robin's injury is a massive blow. It seems that it is the injury that everybody is having - that metatarsal thing. 'He has been doing tremendously well so it is big blow for us and a big blow for him. I just hope he can come back as quick as possible. He has been doing some great stuff for us. It is weird this kind of injury.' Arsenal's fine win has boosted confidence at the Emirates Stadium and Henry claims there is still hope when it comes to the task of catching United. Henry added: 'I think there is still hope. Obviously it will take a massive task for us to win it. But it is mathematically doable. It will take something special to catch Manchester United.' With champions Chelsea losing 2-0 at Liverpool the top two in the table both suffered defeats. Henry added: 'I just think it was a good weekend for Liverpool and for us. But if you don't carry on then it won't mean anything. 'You need to [go on] and make sure you can remember this game and say it was the turning point. 'At the moment it is a great win don't get me wrong but, as I said, I would rather be top of the league than do the double (over Manchester United). 'It is always something great to beat Man Utd. But at the same time it is important to go on a great run now and make sure you can capitalise on the big game we had yesterday. 'We lost so many points at home at the beginning of the season but against United we showed we can play some great stuff. Now we need some consistency and to pick up points game by game. 'You can't moan if you are 12 points behind. It is for a reason. Now we have to grab points we can grab. 'It was a pleasure to beat United in the way that we did it yesterday. It was the second time we won a game coming from behind. The first was against Blackburn so to do it against a team like that was great. 'In the past weeks we have been scoring a lot of goals in the dying minutes of the games so that tells you that most of the squad is on form because we finish the game well. 'And it has come at the time of the year when you are usually tired from the Christmas period. I don't know if we are stoppable or unstoppable. That is not the point. We know we can deliver something throughout the whole game and that is important.' Henry has scored in all four games since his return from a hamstring injury against Charlton earlier this month but insists he is not firing on all cylinders just yet. Henry added: 'I am getting there. I have said so many times. I had to do a pre-season this season. Ten days of training at the start of the season to prepare is not enough. So what did I do with the staff and the fitness coach while I was out? I did a pre-season. I am starting to feel better and better now. 'I have played 15 games and scored nine goals. I was getting hammered (by the critics. But that is not a bad ratio. When you don't do what you usually do, you get hammered. That is just the way it is. 'I just want to be fresh and help my team. Everybody is helping each other. When you saw the way we played at Blackburn with 10 it was tremendous. 'When you look at the first goal against United it was all about desire. The way that Cesc Fabregas and Tomas Rosicky fought for the ball was tremendous. 'When the cross came in I said to myself `shall I hit it?' but then I thought I have no right to hit that. So I just tried to flick it to the back post. To be honest I got lucky. I just wanted to keep the ball alive and then Robin arrived at the back post to score. 'The whole move was about desire and commitment. But it is a team game and if you want to achieve anything then you need to work as a team. We are doing that at the moment.'