Jennifer Lopez At Ukraine Wedding Gig: "I'm Happy!"

CRIMEA, Ukraine -- Just four days after announcing the end of her 7-year marriage to Marc Anthony, Jennifer Lopez proved she's still a superstar -- and a professional -- during a work trip to the Republic of Crimea in Ukraine on Tuesday.

Lopez, 41, was paid a reported $1 million to sing at the lavish wedding of the son of Azam Aslamov, a Uzbek oil tycooon.

Arriving early Tuesday morning with a large entourage of dancers, backup singers and make-up artists, the American Idol judge checked into the $4,100-a-night penthouse suite of the hotel Ville Elena.

After spending much of the day inside, Lopez and her crew emerged to leave for the bash and was "very pleasant" to the staff, manager Yekaterina Komarova said.

"[She] greeted everyone, smiled a lot," thanking the staff and signing the guest book -- and even signed autographs and took photos with fans.

Held at a recreational complex on the Black Sea coast, the lavish wedding itself is reported to have cost up to $15 million -- with 500 guests, some of them arriving via helicopter; super-tight security and 100 waiters presiding over the feast.

During her performance, an ebullient Lopez wowed the crowd.

"Are you happy?" she exclaimed onstage. "I am happy, because I am here with you today!"

Indeed, although one pal says Lopez is "devastated" and "beside herself" that she and Anthony, 42, have called it quits, "she is looking forward to the future," another confidante says in the new Us Weekly, out now.

"She is jumping back into work and being a mom [to twins Max and Emme, 3] with all her energy and she is really excited. She feels like she has grown leaps and bounds and is a new person now, better than ever!"

Source: US Magazine