Original Starz drama “Power,” which had been picking up ratings steam in July and has been especially popular among African-Americans, surged Saturday night in its finale to hit series highs that more than doubled the audience of its premiere.

According to Nielsen, the initial 9 p.m. telecast of “Power” averaged 1.082 million viewers — up from 754,000 one week earlier — and two quickie replays brought the show’s total for the night to 1.769 million. Counting all airings over the weekend, its nearly 2.5 million viewers is the largest total audience for a Starz finale since the conclusion of “Spartacus: War of the Damned” in April 2013.

The June 7 series premiere of “Power,” whose executive producers include Curtis “50 Cent” Jackson, had drawn a modest 462,000 viewers for its initial airing. But it steadily grew throughout its eight-week run.

Despite being in considerably fewer homes than most basic cable networks, the season finale of “Power” at 9 p.m. drew more adults under 50 (660,000) than the season premiere of AMC’s “Hell on Wheels” (597,000) in the same time period. It drew a balanced gender mix, with 50% of its adults 18-49 audience and 49% of its adults 25-54 audience coming from men.

Starz said that prior to the finale, episodes of “Power” had been averaging about 4 million viewers across all platforms, including Starz on Demand and Starz Play. It has been renewed for a 10-episode second season.

Looking to strike while it’s hot, “Power” will premiere to more than 10 million new households on Encore Black starting Aug. 12. The show will premiere one episode per week on Tuesdays at both 10 p.m. and 11 p.m., leading up to its Sept. 30 finale.

The freshman season of “Power” derived roughly 71% of its audience from African-Americans, according to Nielsen estimates provided by Starz, making it the most highly concentrated black audience for a scripted premium series since HBO’s “The Wire” in 2006. And among all current series airing on premium cable networks, only HBO’s “Game of Thrones” and “True Blood” drew larger overall African-American audiences than “Power.”

“Power” stars Omari Hardwick as the owner of a New York City nightclub who is also a player in one of the city’s biggest illegal drug networks. Lela Loren, Naturi Naughton and Joseph Sikora also star.

It was created by Courtney Kemp Agboh, who serves as executive producer and showrunner. Mark Canton, Randall Emmett and David Knoller (“Big Love,” “Carnivàle”) also serve as executive producers. The series is produced in association with CBS Television Studios.