A win against Brighton would have improved Arsenal's title fight with Manchester City, but Arsenal's 3-0 defeat against Brighton meant that Manchester City went well ahead of Arsenal on points. 

Arsenal are 4 points behind Manchester City after playing one more match. If they had won against Brighton, Arsenal would have had 84 points and Manchester City would have had 85 points, that is, the two teams would have been equally ahead in the title fight, but it did not happen. 

Manchester City may be going for the league title along with the Champions League title this season.