Arsenal, Liverpool and Chelsea are considered the hot favorites for this year's Premier League title. So, if Arsenal wanted to stay ahead in the title race, they would have to earn points against Liverpool. Arsenal has already fallen behind in the title race due to the defeat in this match.
This three teams are really considered title favors right, which I think it's right because Manchester City don't seems to be at their best and Manchester United in my opinion is not in the mix.
Arsenal losing to Liverpool is really not the end for them and I still see them as a serious contender. They really did not played badly in that match and I think it's a balanced match that could have gone either ways, but Liverpool won it with a goal deserving of a win.
Arsenal has not lost to the big six in the last to seasons till this match, so I don't think this losing will define their season, but it would have been a statement for them.if they had won at Liverpool, but the lose still does not make them.less a contender.