The capital club, who emerged from a string of frustrating seasons to finish sixth last term, had looked like title contenders in their first few matches of the campaign.
Last weekend, however, they collapsed in the last five minutes at Monaco, conceding two late goals to lose 2-0 and drop to fifth place, three points off the lead.
To make matters worse, Benin midfielder Stephane Sessegnon, arguably PSG's best player, was sent off for a nasty challenge in the closing stages and will be suspended for the match against Lyon on Sunday.
"Moments like these are difficult to handle," said Brazilian defender Ceara, aware PSG need to bounce back straight away.
"Even without Stephane, we will play a great match against Lyon," Ceara told reporters. "Everybody's waiting for that one. I believe we can live up to it and beat Lyon."
"They are having a good run but we're ambitious and we must win our home games, no matter who we face," Ceara said.
