Chelsea might find it tough to break down Palmeiras defense when both of these teams play against each other in the quarter finals as Palmeiras are one of strongest team in defense as they had only conceded a total of 2 goals throughout this tournament. I think there is a very high chance for this upcoming match to ends up in a draw between these two teams and extra time or even a penalty shootout might be needed to decide the winner team.
I have the same thoughts... Chelsea is probably more famous than Palmeiras, and they might be at a slightly better level, but that doesn't mean they will beat Palmeiras, and I think it is even possible that the opposite will happen, because Palmeiras although not very prominent in this tournament (they have not faced a big team before Chelsea) but their performance is quite consistent.
Apart from that, Chelsea once lost when facing Flamengo, who also came from Brazil like Palmeiras, so I think Chelsea will face tough resistance when facing Palmeiras.