Sting put strong winds in the sails of his Broadway musical last week, with the musician’s first performances in “The Last Ship” adding significant momentum to the production’s previously middling box office.

The composer of the semi-autobiographical musical, who joined the cast Dec. 9 in an effort to boost the largely well-received but sales-challenged show, drove sales up to $817,897, a new high for the production and some 66% higher than the previous week’s tally. It wasn’t quite enough to pack the house, however, with audiences filling the 1,350-seat Neil Simon Theater to an average of 77% of capacity.

Still, last week’s B.O. total represents a major improvement for the production, and the high-profile cast addition looks poised to drive box office even higher as tourists hit Broadway in droves during the ultra-profitable Christmas-New Year’s frame. To keep business strong during the annual January slowdown, Sting has already extended his stint in the show by two weeks (until Jan. 24).

The major bump at “The Last Ship” —  plus notable ones at Bradley Cooper starrer “The Elephant Man” ($934,580) and “The Illusionists” ($987,234),  both rebounding after their opening weeks — helped counteract an overall downshift that wasn’t terribly dire.

With a number of shows declining but few doing so by very much, the week’s Broadway cume came in at $30.1 million for 36 shows on the boards. Attendance remained relatively steady at 273,383, or about 80% of total capacity. The average price paid per ticket, a good indicator of overall demand for Main Stem tickets, remained steady at $110.05.

Among the shows closing in January, “Cinderella” ($851,242) seemed to get the biggest infusion of last-minute business last week, although titles including “Pippin” ($468,537), “Rock of Ages” ($376,586) and “This Is Our Youth” ($270,455) — all closing next month as well — held steady.

Not all shows benefited from an impending closing, however. “Love Letters” ($274,612), which hastily posted a closing notice last week, fell significantly in its last frame, while “Side Show” ($467,909), which also announced last week it would close, has yet to see B.O. pickup.

Meanwhile, the one show currently in previews, “Honeymoon in Vegas” ($396,473), continues to have trouble turning the heads of holiday audiences more geared toward better-known stage properties.

To judge from prior years, sales will remain similarly robust over the next couple of weeks until the year-end holidays drive B.O. even higher. After that comes the January slowdown that annually winnows down the Broadway slate, ahead of the new shows that blossom on Broadway in the spring.