The PSG boss was enthused by the way in which his side exploited the Blues' fatigue in the second half at the Parc des Prince but he is taking nothing for granted.
Terrific strikes from the Argentine duo of Ezequiel Lavezzi and Javier Pastore and a David Luiz own goal earned the French champions a stirring 3-1 win at Parc des Princes.
However, delighted as he was by PSG's response to Eden Hazard's first-half equalizer from the penalty spot, Blanc is taking nothing for granted ahead of the return fixture at Stamford Bridge.
“It is encouraging,” the World Cup winner told reporters after the game. “But qualification is far from being acquired. I felt the team was a little dejected [at 1-1 at halftime] but I told them that they should return with a fighting spirit. That's what we did.
"The Blues, they did a lot of running [in the first half], so they were struggling. We are really pleased with the second half; that's where we made the difference.”
Blanc also paid tribute to the much-maligned Ezequiel Lavezzi, who opened the scoring after four minutes before whipping in the free kick that led to David Luiz's own goal, which put PSG 2-1 ahead.
“He was a powerful and important contributor to our success,” said the 48-year-old coach. “He found a good physique. He is sharp; it has not always been the case. But he is one of those players who add depth and speed. In addition, he scores goals.”
PSG, which leads Ligue 1 by 13 points over Monaco, plays Stade de Reims at home Saturday before traveling to London for the second leg of its quarterfinal clash with Chelsea on Tuesday.