Broadway box office surged up 9% in the final week of summer before the Labor Day holiday, with major gains at closing shows — particularly “Les Miserables” — helping to move the needle before the back-to-school downturn hits this week.

The Broadway revival of “Les Miserables” ($1,326,559), wrapping up its two-and-a-half year run, exploded up by about $250,000 (or 24%), propelled by last-minute business and the title’s global recognition, attracting a final influx of New York’s summer tourist crowd. The additional sales elevated the musical to the fifth rung in the Top 10, behind “Hamilton” ($2,091,791), “The Lion King” ($1,867,689), “Aladdin” ($1,449,373) and “Wicked” ($1,408,374).

“Les Miz” wasn’t the only one to get a closing-week boost. “The Curious Incident of the Dog in the Night-Time” ($677,778) posted a gain of $145,000 (up more than 25% from the previous week) before it ended its unusually long (for a straight play) run, and “An Act of God” ($424,289), the Almighty comedy starring Sean Hayes, picked up by 22%.

The closing of the latter two titles leaves Tony champ “The Humans” (up a bit to $548,838) as the last non-musical standing on Broadway. Like “Curious Incident” before it, Stephen Karam’s play seems to have managed to carve out a foothold for itself despite a little-known title and a cast of less-than-famous actors. The show won’t be the only play on the boards for long, however, with projects waiting in the wings including Karam’s new adaptation of “The Cherry Orchard,” beginning previews later this month with Diane Lane leading the cast.

Meanwhile, the first of the fall productions to join the ranks was the Roundabout Theater Company’s “Holiday Inn” ($165,392 for four previews), the stage version of the 1942 movie musical, while the newly retooled Cirque du Soleil show “Paramour” ($890,755 for seven) returned after a quickie hiatus for fine tuning.

Overall Broadway sales climbed by $1.87 million to $23.4 million for 26 shows on the boards, with particularly hefty upticks logged at crowdpleasers like “School of Rock” ($1,072,367), “Cats” ($993,376) and “Beautiful” ($876,530). Attendance rose by 15,000 to 224,722, or 83% of total capacity.

The Broadway box office will almost certainly deflate in the coming week, thanks to the usual post-Labor Day downturn, but helping to counteract that will be the new titles joins joining the boards in the coming weeks. First up: “Black to the Future,” the Lewis Black solo show, as well as “Cherry Orchard” and “The Encounter.”