Ligue 1 round-up: Mbappe bags classy hat-trick as PSG hit six
Vitinha put PSG ahead at the Stade de la Mosson and Mbappe doubled their advantage midway through the first half, only for an Arnaud Nordin header and a Teji Savanier penalty to bring Montpellier back level at the interval.
However, a marvellous Mbappe goal restored PSG's lead shortly after the break and Lee Kang-in made it 4-2 before the France captain completed his hat-trick.
Nuno Mendes put the seal on the victory late on, as Luis Enrique's side ended a run of three successive draws in Ligue 1 and extended an unbeaten domestic record stretching back to September.
A 1-1 draw for nearest challengers Brest against Lille means the Parisians are 12 points ahead at the Ligue 1 summit with only eight games left, and a 10th title in 12 seasons is an inevitability.
Mbappe completed the whole 90 minutes of a Ligue 1 game for the first time since informing the club in mid-February that he intended to leave at the end of the season when his contract expires.
His hat-trick, his third of the campaign, took him to 24 goals in Ligue 1 this season, and 38 in all competitions.
Mbappe's second of the evening, PSG's third, was the pick of the bunch, as he found the net with a superb shot from range which went in off the underside of the crossbar.
"Mbappe was exceptional. We need to make the most of having him, as much as we can, and when we can no longer enjoy having him we will have to raise our game," said Luis Enrique.
The downside of their performance came with the way in which they surrendered their 2-0 lead in the first half, conceding the penalty when Tanguy Coulibaly pounced on Danilo Pereira's short back-pass and was then clattered by PSG goalkeeper Gianluigi Donnarumma.
The defeat for Montpellier leaves them just a point above third-bottom Nantes, who are in the relegation play-off place and on Sunday sacked coach Jocelyn Gourvennec.
Canadian striker Jonathan David continued his superb form in front of goal by scoring for Lille in their draw away to fellow Champions League contenders Brest.
David gave Lille the lead midway through the second half in Brittany with his 22nd goal of the season in all competitions, and his 15th since the turn of the calendar year.
The 24-year-old has netted 10 times in his team's last nine Ligue 1 outings. His total of 15 in Ligue 1 this season is bettered only by Mbappe.
However, that goal was not enough to win the game, as Uruguayan striker Martin Satriano poked in a late equaliser for Brest, who remain second.
Ito hits winner for Reims
Monaco could have climbed above Brest with a win at home to Lorient, but they were held to a 2-2 draw after Tiemoue Bakayoko headed in a 95th-minute equaliser for the struggling away side in the principality.
Monaco remain third, three points above Lille who reclaimed fourth from Nice, 3-1 winners at Lens on Saturday.
The top three in Ligue 1 go straight into next season's Champions League, with fourth entering the competition in the third qualifying round.
Rennes boosted their hopes of qualifying for Europe with a 2-0 win at home to Marseille, as Martin Terrier put the hosts ahead in the first half and Benjamin Bourigeaud added a late penalty.
Both sides are now three points adrift of the final European qualifying spot.
Japan star Junya Ito fired in a superb 79th-minute strike to give Reims a 2-1 win over Metz which keeps his club in the European picture.
Oumar Diakite had put Reims in front early on but Arthur Atta equalised before the decisive goal from Ito, who was left out of the Japan squad to face North Korea in upcoming World Cup qualifiers.
Ito left the Asian Cup last month after Japanese police said he was under investigation over an alleged sexual assault in Osaka last year.
The player denies the allegation and is suing his accusers for damages.
Reims coach Will Still described the 31-year-old winger as "mentally strong and faithful to himself".
Bottom side Clermont kept their outside survival hopes alive by beating Le Havre 2-1 with a brace from Muhammed Cham.
