Despite losing, Arsenal actually played quite well and had several good chances which could have been goals. It's just that Emiliano Martinez played very impressively and managed to thwart several opportunities that Arsenal had. This is certainly a heavy blow for Arsenal, though they dominated the game and had more chances than Aston Villa, but that still doesn't guarantee that they won't lose to their opponents because in football anything can happen.
Ben White gave John McGinn enough time to hold the ball and turn before he struck to get the only goal of the game. This was a huge carelessness on the side of the Arsenal defender. Arsenal controlled the game but they were also wasteful. Martin Odegaard had two clear-cut chances that would have sealed Arsenal's victory but he wasted them. The best players in the Arsenal side were Gabriel Jesus and Bukayo Saka who constantly put the Aston Villa defence under pressure all through their stay on the pitch.
Aston Villa is gradually becoming a force in the EPL under Unai Emery. The club has moved to third position and will maintain the position regardless of the outcome of the Manchester United and Luton Town game, but if the games end in a draw like it is now, Aston Villa will be four points ahead of the current EPL champions.