Due to the illness of soloist concert performance is cancelled.
The square next to the inn is full of people. Among them is a group of students, chatting happily with one other. The liveliest of them, Edmondo, is teasing the melancholy Chevalier des Grieux: Edmondo believes his friend is having relationship troubles. Des Grieux replies that he knows nothing about love. The conversation is interrupted by the arrival of a coach, which is transporting Sergeant Lescaut, his sister Manon and Geronte, an old, wealthy tax collector. Charmed by Manon’s irresistible beauty, des Grieux waits for a moment when Manon is by herself to approach her. The Chevalier learns her name and that she is on her way to a convent by order of her father. Manon’s brother calls to her from the inn’s balcony. She promises des Grieux that they will meet again.
The old Geronte also expresses an interest in Manon. Lescaut makes no attempt to dissuade the wealthy Geronte – such a union would benefit him as well. Geronte secretly plans to abduct Manon: while Lescaut’s attention is devoted to his card game, the old Geronte orders the Innkeeper to bring a coach around in an hour. Edmondo hears all of this and hurries to inform des Grieux of Geronte’s plan. Having been warned of Geronte’s intentions and invited to run away to Paris instead, Manon grows flustered, but des Grieux’s impassioned plea persuades her.
Lescaut comforts the tricked Geronte: Manon’s happiness will soon come to an end when the pair runs out of money.
Manon sits in her fancy boudoir in Geronte’s home, getting ready for the party later in the evening, but she can’t quell her desire to be with des Grieux in his modest accommodations. Musicians enter, playing a madrigal Geronte composed specially for Manon. Manon is bored. Lescaut decides to go find des Grieux while Manon is having a dance lesson. Manon and Geronte dance together, admired by their guests.
Manon finds herself alone for a moment. Des Grieux enters and chastises Manon for her infidelity. Manon begs his forgiveness, and finally the pair embraces once more. Geronte enters to find them. He then leaves them, hurt, but promises he’ll soon return.
Lescaut enters, out of breath – Geronte has ordered Manon’s arrest and the guards will arrive any moment. Desperate, Manon tries to gather her jewels, but it’s too late to escape.
Des Grieux and Lescaut are planning to break Manon out of prison with the help of a bribed guard. Des Grieux and Lescaut meet before dawn in the square next to the port and the prison: Lescaut goes to organize his sister’s rescue; meanwhile des Grieux talks with Manon through her cell window. An alarm sounds – their plan has failed. Followed by a loud crowd, the Sergeant checks over the list of women to be deported. Manon, who will soon be shipped off, asks des Grieux to forget her. In despair, des Grieux appeals to the port commander. He takes pity on de Grieux and lets him on board.
Their strength waning, Manon and des Grieux wander a desert near New Orleans. Des Grieux goes to find shelter, but to no avail. Manon dies in his arms.