Melanie La Barrie thought she would make it through her last performance of “& Juliet” without succumbing to tears.

She was mistaken — though contributing factors include that it was the end of a nine-show holiday week; that she originated the role of Angélique, Juliet’s nurse, in this British jukebox-musical riff on “Romeo and Juliet” in 2019; and that she made her Broadway debut in it, at 48, in October 2022.

On Saturday night at the Stephen Sondheim Theater, where “& Juliet” is one of Broadway’s poppiest hits, La Barrie sailed through her comic Act I duet with Paulo Szot, who plays Angélique’s long-lost love. But her poignant Act II solo, sung to Juliet (Lorna Courtney), undid her. Embracing Courtney at the finish, La Barrie kept her eyes shut tight against the audience’s ovation, needing to stay rooted in the show.