Actually PSG failed to win the match despite playing extremely well. The reason for this may be that the team has too many star players or there was something wrong in the management of the coach of the team. Which gets the players in big trouble.
I also don't understand why PSG can lose at home to a mid-table team like Lyon, even though PSG have the best players and even in the first half Lyon had one chance to score a goal through a penalty which was saved by the PSG keeper. But in the second half Lyon again made the lead by scoring one goal and that result was able to bring Lyon to victory even though this result would not affect PSG's position in the Ligue 1 standings.