Arsenal might have won against Manchester City had Trossard not been sent off after receiving a red card in the 45th minute. Arsenal performed brilliantly from the first minute to the 45th minute, but playing half-time with one player down is difficult for any team, and even more so when the opponent is Manchester City. Manchester City attacked after half time and those attacks were only repelled by Arsenal.  

If we discuss from the beginning of the match, then we must first mention Manchester City's goal in the ninth minute. Manchester City scored in the ninth minute, but Arsenal managed to score in two stages in the first half and they were ahead of Manchester City in the first half.  
Arsenal was able to hold this lead until the end of the game but in the last minute they conceded another goal from Manchester City and the game ended here.