They were lucky to win because I don't know what's wrong with Chelsea, they always seem to start games well. However, by the end of the match, they seem to be playing with the ball anyway and start creating goals that aren't necessary. Take a look at the unnecessary foul that Gallagher committed in the final seconds of the first half, which resulted in a red card. they were just lucky to win, their midfield and defence are always at their best, but they still need to focus on that striker.
Maybe you are right, Chelsea was lucky enough to win because Brighton performed quite well in that match and as usual appeared to be a team that appeared to put pressure on their opponents but this time they were not good enough when it came to finishing so they had to accept defeat, and this was quite a tough match seeing how the referee issued quite a lot of cards.
Manchester City were certainly quite disappointed because they had drawn twice in a row in their home matches and that meant they had to be in third place. Tottenham played quite well and a goal in the final minutes of the match from Dejan Kulusevski saved the three points which almost belonged to the home team and for Tottenham this could be the momentum to recover after three consecutive defeats which made their position even lower.