PSG have moved swiftly on since landing their first league crown in 19 years in May, with Italian coach Carlo Ancelotti leaving for Real Madrid and loan star David Beckham retiring.
But awash with cash from their Qatari owners the capital club, touting a budget of 400 million euros, are hot favourites to repeat their success, even if newly-promoted fellow moneybags outfit Monaco will look to push them hard.
Falcao, a 60-million-euro acquisition from Atletico Madrid, is the big draw for the Monegasques, bankrolled by Russian billionaire owner Dimitri Rybolovlev.
But the principality club must begin the season with a two-point deduction after a series of incidents at the end of a game last season.
Montpellier represented a tough opening day test for the Parisians given the southerners' status as 2012 champions though they saw the architect of that win, Rene Girard, switch to Lille in the summer, with Jean Fernandez arriving to replace him.
PSG, now under the stewardship of former France and Bordeaux coach Laurent Blanc, elected to start with a strike tandem of Zlatan Ibrahimovic and Ezequiel Lavezzi, leaving 64 million-euro new boy Edinson Cavani on the bench to begin with at the Stade de la Mosson.
"We expected a better result," admitted Blanc. "But we created too little for my taste and made too many mistakes which allowed Montpellier to score."
Fernandez believed the game could have been wrapped up in the first 45 minutes.
"We could have won the game in the first half. If we had been a little more clear-headed, we could have created more chances. But then we suffered in the second half," he said.
But after an early Lavezzi header flashed off target it was the hosts who scored the opening goal of the new season, a rasping drive from Remy Cabella
after just ten minutes.
Cabella robbed Ibrahimovic and then found Emanuel Herrera, who fired in an effort which was blocked only for Cabella to drive in at the second attempt.
Though enjoying the lion's share of the possession PSG were forced to grind through the gears as they strove to respond and Ibrahimovic sent in a fizzing effort which Geoffrey Jourdren in the home goal tipped away.
A goal to the good at the break, Montpellier could have doubled their lead on 50 minutes but Herrera fired over from the edge of the area.
And PSG finally managed to get back on terms on the hour mark through Brazilian Maxwell.
Javier Pastore fired over a cross form the left which Ibrahimovic just reached at the far post, nodding on for former Barcelona defender Maxwell to net from close range.
Montpellier had a nervous final 18 minutes after their Moroccan defender Abdelhamid El Kaoutari was red carded for a foul on Pastore.
Monaco open their campaign Saturday at Bordeaux, whom PSG's Blanc led to the title in 2009, while other weekend action sees Lyon host Nice and Lille welcome Lorient.
Sunday sees Ajaccio take on former giants Saint Etienne with the former now being coached by former Italy striker Fabrizio Ravanelli.
Newly-promoted eight-time champions Nantes host Bastia on their return.