Slimmer, Trimmer Christina Aguilera

Christina Aguilera has brought the genie out of the bottle one more time — surprising and delighting viewers at last night’s Billboard Music Awards with a sleek, sexy new look and trimmed-down body.

Aguilera, who will soon return to “The Voice” as a coach, has struggled with her weight over the years, most particularly after the birth of her son in 2008. “I’ve been on all spectrums (weight-wise),” Us magazine reported she told reporters at a TCA conference in 2012. “I’ve been in this (business) for a long time. You can never be too perfect, too thin, too curvy, voluptuous this, that. I’ve been on all sides of the spectrum as far as any female in this business.”

Of course, anyone who’s been keeping an eagle eye on the 32-year-old in recent weeks knew she’d had a bodacious bod remake, showing it off at the “The Voice’s” season 4 premiere in March and again at the 2013 Time 100 Gala in April.

But onstage Sunday night in a mini dress, belting out “Feel This Moment” with Pitbull, she wasn’t just strolling down the red carpet — but in her element, on stage. And she looked terrific.

Still, Aguilera does seem to have her head on straight about her body. In 2012, when she was a few sizes larger, she told People that “I embrace my body, and I embrace everything about myself…. I’m embracing everything that I’ve grown to be and learned to be.”