PSG, fourth in the Ligue 1 and five points off the pace after they losing three of their last five matches, beat Porto 2-1 on Tuesday to top their Champions League group with 15 points from six games, two ahead of the Portuguese.
"To be honest, I was not thinking the match could go as well," PSG captain Thiago Silva, who opened the scoring at Parc des Princes, told reporters.
"It is not good from us, but we are more focused when we play big guns like Porto than modest Ligue 1 sides."
"We were playing with four forwards. It shows that we can do well if we all have give our best and apply the coach's orders," the Brazilian added.
The former AC Milan player was one of the major signings in the off-season, when PSG went on a 150 million euros spending spree.
Apart from Zlatan Ibrahimovic, the French league's leading scorer with 13 goals in 12 appearances, most have failed to deliver so far in Ligue 1.
Argentine's playmaker Javier Pastore, who signed last year for a then French record fee of 42 million euros, produced one of his best perfomances on Tuesday.
"We have to be more concentrated every day at training and in every game," Thiago Silva added. "We can not expect Ibra to hand us the victory each and every time. This is not how it works."
Coach Carlo Ancelotti said: "The Champions League has been very demanding, both mentally and physically. It was very, very important for us to reach the last 16.
"The players may have been turned their eyes more on the Champions than the league.
"It is not good to trail Lyon by five points. But if we are able to display the same attitude in the league, we would recover fast."
