Clad in a version of the bedazzled bodysuit she wore a decade ago in the video for her song “Toxic,” Britney Spears launched her much-discussed two-year residency at Planet Hollywood Resort & Casino by emerging from a giant metal globe suspended over the stage of the Axis Theater. “Work Bitch,” the lead single from her latest album, thumped through the venue’s booming sound system as an army of masked dancers marched around her. Smoke swirled, fans hoisted miniature bottles of Moët & Chandon.

For a few tantalizing moments Friday night, Spears -- the one-time teen-pop queen who’s spent much of the last few years inching back from the brink -- seemed ready to reclaim her once-vivid form. Then the bubble burst.

Scheduled to run through 2015, with Spears playing approximately 50 shows a year at the 4,600-seat Axis, “Piece of Me” represents a potential pivot point for the singer and the state of entertainment on the Las Vegas Strip.

For Spears, 32, the steady gig promises a path out of the turmoil and disappointment that have surrounded her since 2007, when she attacked a paparazzo’s car with an umbrella after shaving her head at a Tarzana salon.

Though Spears’ personal life appears to have stabilized, her career is still hurting: This month her album “Britney Jean” opened with the lowest sales of the singer’s 15-year career; it sits at No. 27 on the Billboard 200, well behind records by Katy Perry and Miley Cyrus, both of whom showed up Friday night as a sign of respect to a trailblazer.

Filling the Axis, the thinking seems to go, might restore some of Spears’ luster without her having to engage in direct competition with her younger successors.

Las Vegas, meanwhile, stands the chance to further dismantle its reputation as a home for has-beens. Successful casino shows by the likes of Celine Dion and Elton John have advanced that effort, but with its jackhammering dance beats and recent-vintage radio hits, “Piece of Me” bridges the gap between those old-school extravaganzas and the superstar DJ sets that have increasingly come to define the city’s night life.

In terms of show-business strategy, it seems to make sense. Yet as a concert experience Spears’ opening-night performance came up awfully short.

Like most Vegas revues, “Piece of Me” moves briskly, packing two dozen of Spears’ songs -- from early smashes such as “… Baby One More Time” and “Oops! … I Did It Again” through last year’s “Scream & Shout” and the new album’s “Perfume” -- into a 90-minute sprint that offers the star only a few opportunities to catch her breath.

Plenty happens in that hour and a half. In “I Wanna Go” she danced with digitized versions of herself seemingly reflected in several faux mirrors -- think Snow White in Sin City -- while “Scream & Shout” featured a pair of neon-clad dancers running on gigantic hamster wheels.

For “Toxic” the stage transformed into a lush jungle tableau, a convincing attempt to keep up with the various eye-popping Cirque du Soleil shows in production across Las Vegas. And “Everytime” found Spears suspended over the stage again, a stories-tall gown flowing beneath her.

Smaller moments complemented the elaborate set pieces, as when Spears did a stripped-down rendition of “Lucky” set to a forlorn music-box arrangement.

Whatever the scale of the number though, the singer’s presence felt so diminished -- her dancing a tentative shadow of what it used to be, her vocals apparently lip-synced for the majority of the show -- as if to make the production’s title seem a taunt.

That was never more true than in the song “Piece of Me,” which on 2007’s “Blackout” -- perhaps Spears’ best album, released right in the thick of her public meltdown -- arrived like a searing indictment of the tabloid surveillance state. On record the track still stings, yet here it flat-lined, with none of the intensity, energy or strut that made Spears such a focal point of mainstream pop.

Throughout Friday’s concert the singer seemed merely to be marking the type of moves she once nailed to the stage; her boilerplate banter (“What’s up, Vegas? I can’t hear you!”) had a similarly uncommitted quality. To the extent that Spears had anything to say, it was overpowered rather than accentuated by the lights and the sets and the clips from her iconic music videos that played each time Spears ran offstage for a costume change.

You can understand her difficulty in meeting these demands. A decade (and two children) after her commercial peak, she’s in a dramatically different position than she was during the days of “Me Against the Music” and “I’m a Slave 4 U.”

Her life, one presumes, no longer allows for leaving it all on the stage.

But then why put her in this show, which neither revisits her old mode effectively nor presents a compelling new approach? “Piece of Me” demonstrates only loss; it suggests that instead of looking forward, Spears (and her handlers) are playing a dangerously cynical short game, exploiting the interest her name still inspires without regard for how the act’s shoddiness may limit her future options.

Spears’ game needn’t be over, yet she’s cashing in all her chips.