Paris Saint-Germain striker Zlatan Ibrahimovic believes that every game will be a difficult one in the Champions League.

The Ligue 1 champions opened the competition with a 4-1 win at Olympiacos on Tuesday night thanks to goals from Edinson Cavani and Marquinhos either side of a Thiago Motta brace.

Despite their large scoreline, Ibrahimovic, who missed a second-half penalty, insists that it was not an easy match.

"It may have seemed easy to get the win but it wasn't," Ibrahimovic told reporters. "The Olympiacos fans created an amazing atmosphere and this was a great advantage for them in the first half.

"Our goal is to advance to the next stage and we got three very important points that set us on our way to qualification. If we finish top of the group or not is not really important.

"All the games are difficult in this competition and we cannot afford to underestimate any opponent. I had spoken with [former Olympiacos defender and Sweden teammate Olof] Mellberg and he told me that the fans here are fantastic; eventually I had that experience and the atmosphere was incredible."

PSG host AS Monaco at the Parc des Princes on Sunday.