It's a two-horse race - Koscielny
Victories for both teams in midweek have helped to edge them clear of the chasing pack. United are now five points clear at the summit, and still unbeaten, while Arsenal have opened up a three-point lead over third-placed Manchester City. Koscielny expects the top two to lead the charge, with Arsene Wenger's men looking increasingly like the only side who can prevent Sir Alex Ferguson's Red Devils from reclaiming the crown they surrendered to Chelsea last term. He said: "It looks like we are the last challengers to United. We have got more points than Manchester City, Chelsea and the others. "We need to focus on our game, keep winning, keep picking up points and maybe United will lose games at some point. "Anything can happen in this league. That's why we must keep working hard together. We will keep fighting. It's important we keep our defence strong. "If we don't concede, we will always make chances to score ourselves. "It's going to be a big battle between us and Manchester United and hopefully they will drop points, not us. "It's not going to be easy. But we have faith in ourselves and in the squad. We do believe we can do it so bring it on." French central defender Koscielny has also admitted that he found the transition to life in the Premier League difficult following a summer switch from Lorient, but believes he is improving all the time. He said: "It wasn't easy for me but I feel stronger. I definitely feel like a better player than when I arrived here. In the last two months I have felt I've improved a lot."