you are right I thought Arsenal could not win the match. But Arsenal were very lucky. If Arsenal were not lucky, the team would not have been able to get 3 points from this match. Leicester City were not strong opponents. However, Arsenal's performance was poor.
To rate Arsenal's performance as a poor performance is not fair, if you watch the match, you will understand what I am saying. Arsenal didn't perform to their peak as expected, but they did their best in the game. Suppose you have been monitoring Arsenal games since Odegard got injured. In that case, you will notice that Arsenal was struggling to win matches even after several struggles, we only scored confidently on setpiece because the main attacking midfielders that were supposed to be with the squad were all injured. Still, the manager is trying his best to improvise and use his other options to make the team win games.
This is true as we saw Arsenal's dominance in the first half of the match. It was 2-0 at the end of the first half. We thought Arsenal was going to get an easy win in this match, as the opponent Leicester is not a strong team. But Leicester scored two consecutive goals in the second half to level the match at 2-2. Leicester city players managed to score two goals despite not attacking much. This shows that Arsenal's defenders did not do well in this match.
You are right, Arsenal dominated the first half and got two goals, but Leicester City came back strong and got two goals which they were defending before Arsenal could get the last two goals. Leicester City's goalkeeper made a lot of saves today, he saved his team from conceding a lot of goals because Arsenal dominated the game.
A lot of attacks were carried out by Arsenal players throughout the match. But Arsenal scored the last two goals after 90 minutes. More importantly, Arsenal's third goal was a mistake by Leicester's Ndidi.
That shows that the Arsenal squad of this season has a winning mentality, they don't want to give up easily which is why they keep putting pressure until the final wistle and they get the three points.