Lavezzi was asked to lead the line as the centre-forward by coach Carlo Ancelotti and despite it not being "easy", the Argentinian scored the crucial goal for his side in the 1-1 draw with Valencia on Wednesday night.
"Ibrahimovicc is a top player and he's very important for the team," UEFA.com quotes Lavezzi as saying. "We knew that without him we'd need to work even harder and make a sacrifice to go through.
"This is a very challenging and exciting competition. It's important to be playing in knockout matches like these - it gives you extra motivation. You have to be 100% focused and never relax."
Lavezzi has scored five Champions League goals this season for PSG.