The Argentinian netted two finishes, including a superb bicycle kick, after goals from Neymar, Achraf Hakimi and Marquinhos got the champions off to a dominant start at Stade Gabriel-Montpied.
On the back of last weekend's Trophee des Champions victory over Nantes, it marks two wins from two for new coach Christophe Galtier following his arrival at the Parc des Princes.
But it will be the manner of their result that pleases supporters most despite the absence of star man Mbappe through injury, with the France international yet to play a competitive fixture since committing his future to the club.
Having struck gold in Israel last month to claim the first silverware of the season, Neymar was on song again for PSG in the ninth minute, producing a low finish following Lionel Messi's neat flick.
The Brazilian turned provider just over a quarter-hour later, passing across the field to the feet of Hakimi, who powered his shot past goalkeeper Mory Diaw to double the visitors' lead.
Any distant hope Clermont may have held of clawing a result back was then duly extinguished seven minutes shy of the interval, when Marquinhos rose to head in a Neymar free-kick delivery from left flank.
With a three-goal cushion to their name, the need to raise the tempo proved less pressing for PSG after the break, and with little in the way of stubborn resistance from their hosts, victory proved a foregone conclusion.
But the best was yet to come from Argentina star Messi, who saved his fireworks for the final 10 minutes, turning a flat Neymar ball home for his first and then unfurling an overhead kick for a stunning second to wrap up the three points in style.
The 34-year-old former Morocco captain played a part in five consecutive league championship wins, firstly when landing two Bundesliga titles at Bayern in the 2014-15 and 2015-16 seasons.
He joined Juventus from the German giants and featured in each of the next three campaigns as the Turin giants mopped up successive Scudetto triumphs, also leading his country at the 2018 World Cup.
Benatia was born in France and began his career in the Marseille youth set-up. He shot to prominence after a move from Clermont to Udinese in 2010, which paved the way for a switch to Roma in 2013, and one year later he was prised away by Bayern amid a scramble by elite clubs for his services.
After a double-winning second season, Benatia moved on to Juventus in 2016, before leaving the Bianconeri to sign for Qatari outfit Al-Duhail midway through the 2018-19 season.
While at Juventus, he was part of the squad that reached the 2016-17 Champions League final and also won the Coppa Italia twice. Most recently he has been with Turkish Super Lig side Fatih Karagumruk, who said Benatia had retired because of injury.
Responding to Benatia's announcement, which he revealed on Instagram, Juventus striker Paulo Dybala sent a heart emoji to his former team-mate. Ex-Bayern winger Franck Ribery did likewise, with current Juve full-back Juan Cuadrado and former favourite Sami Khedira also among those that sent greetings.
Blaise Matuidi, the former Juventus and France midfield general, wrote: "What a career, my brother. I remember those days at [French national football centre] Clairefontaine where we began to dream of being a professional footballer, but by dint of work you did much more than that. Incredible clubs, captain of a nation and having won a good number of titles, you can only be proud brother."
Manchester United defender Eric Bailly joined in the praise, writing: "Bravo capitano. Great man, great career, very good player and finally an example."
Paris Saint-Germain full-back Achraf Hakimi praised his former national team skipper, with the message: "Capitanooo. Good luck in your new stage big bro."
Announcing his decision to retire, Benatia said: "From a young age I had only one dream, to become a professional footballer. To get there, I had to force myself to work hard, make sacrifices, but above all set new goals at each stage of my career.
"This job has also allowed me to defend and represent my country, Morocco, with whom I have experienced unforgettable moments... in particular the 2018 World Cup."
Without Lionel Messi and Neymar, who along with Leandro Paredes and Angel Di Maria were given extra rest following their international exploits in midweek, PSG still made light work of sealing a fifth straight win.
Passed fit to feature after sustaining a calf injury while on France duty, Mbappe – the subject of three failed bids from Real Madrid at the end of August – scored his fourth goal of the season on a typically blistering counter-attack 10 minutes into the second half.
Herrera's first-half double had put PSG into a comfortable position, with promoted Clermont failing to test debutant Gianluigi Donnarumma despite plenty of attacking intent as Idrissa Gueye wrapped up an emphatic win.
Mbappe created PSG's first chance after 11 minutes, though Marquinhos was unable to direct the forward's free-kick either side of Arthur Desmas.
Clermont's resolve was punctured in the 20th minute, though – Herrera on hand to head home after Desmas had parried Achraf Hakimi's cross-shot.
Danilo Pereira would have made it 2-0 four minutes later if not for Akim Zedadka's block, yet PSG would not be denied for long.
Herrera was once again in the right place at the right time to pounce on a loose ball, this time lashing a finish into the roof of the net, while a goal-line block prevented Julian Draxler netting a third before half-time.
There was to be no such reprieve for Clermont early in the second half – Mbappe rounding the goalkeeper to finish coolly after racing onto Draxler's lofted pass.
Mbappe should have doubled his tally, or teed up Rafinha, just after the hour, only for the youngster to chip wide when one-on-one with Desmas.
He atoned moments later, a rebound from his shot falling to Gueye, who nodded in at the back post to cap off a slick display.
