The Frenchman lauded the Argentine's return to form after his difficulties earlier this season, and praised his team for bouncing back from their shock loss to Evian
The Argentine started his first game since October at the Parc des Princes and broke a goal drought that stretches back to August with a fine finish after being put through by Thiago Motta.
"[Lavezzi] was good, better, much better," Blanc told reporters. "I've been strict with him since he can do better, and he agrees with me.
Blanc was buoyed after watching his players make amends for Wednesday's shock defeat at Evian in fine style, with Zlatan Ibrahimovic hitting a double after earlier setting up goals for Thiago Silva and Edinson Cavani.
"We've been eager to get back on the pitch to prove it was a mere accident and not the start of a collapse," he said of their surprise loss at the Parc des Sports in midweek.
"I say well done to the players; they gave a response."
Goalkeeper Salvatore Sirigu was just as enthused that PSG had put their shock setback at Evian firmly behind them.
"There is no such thing as a perfect record," the 26-year-old said. "But I think we are doing exceptional things.
"This win is not a message to others. The important thing is to stay focused on our goals. This is football. We wanted to bounce back and respond after Evian."
The French champions have now opened up a four-point lead at the top over second-placed Lille, who travel to Bordeaux on Sunday.