PSG has its awkward moment when players are out of form and doing badly.
PSG is expected to win for several reasons, as you said Lyon isn't that top this season, PSG lost many points lately and will try to avoid more losses especially that they aren't used to not win for several rounds.
Yes, sometimes, PSG has its bad game when playing or against small clubs. Well, maybe because of some factors.
Actually, with all conditions and factors, PSG has more than enough: big players, great management and fund, and many things are likely completed in that club. But once more, sometimes, they are still doing some mistakes or something that makes the fans disappointed or cannot satisfy their fans with good games.
Fortunately, the point gap between PSG and other clubs is high enough so that it still can put PSG in the top standing and maybe cannot be defeated.
This is the interesting thing about football, sometimes having strong finances and having many star players does not guarantee that a team will
always win. There are so many factors that influence so that a team can win, that's why PSG have failed several times to win. So the Lyon vs PSG
match might be a surprise, indeed if we see Lyon's performance has been very bad this season. So PSG should be able to beat Lyon easily,
but we have to remember that PSG only drew against Lorient. So it's still open to the possibility that Lyon will win the match, especially since
the previous season PSG failed to win the Ligue 1 trophy. So this should motivate Lyon players not to be afraid to face PSG, although it must be
admitted that Lyon's chances of beating PSG are very small.