Jennifer Lopez had more than a shimmering, nearly nude body suit in her arsenal to upstage her estranged husband, Marc Anthony, at the American Music Awards — she also made sure she performed before he did and with a much bigger production.

The superstar “Idol” judge danced provocatively in a skintight bodysuit on the Sunday night show, with her new, muscled, 24-year-old boy toy, Casper Smart, dancing shirtless nearby.

A source told us, “J.Lo also would only allow Marc to perform at the AMAs if she performed on the show first and had a much bigger number than him . . . which is what happened. She had two stages and he had half a stage for his later performance. The only thing they shared that night was Pitbull,” who performed with both.

J.Lo proved she could even steal the show with her new beau at the after-party at Greystone Manor. In an Emilio Pucci sequined minidress with feathers and sparkly stilettos, she danced with Smart to tunes including Michael Jackson and Prince spun by DJ Cassidy. There was no sign of Anthony, with whom she has remained on friendly terms despite their split after seven years in July.

One spy told us, “Jennifer was really affectionate with Casper. She even introduced him to other stars including L.A. Reid.” Lopez’s rep didn’t get back to us. Also at the Grey Goose party was Chris Brown, who “danced topless with his entourage all night,” said a source, adding, “He didn’t even stop when the DJ played Rihanna’s new song. He appeared unfazed, loving the attention.”

Sources tell us there was also tension between Christina Aguilera and her fellow “The Voice” judge Adam Levine during earlier rehearsals for the AMAs, where they performed “Moves Like Jagger.” A spy said, “At the end of the number, Adam went to hug Christina in a friendly fashion, but she pushed him away, gave him a dirty look and stormed backstage.” A rep for Levine told us, “100 per cent not true,” Aguilera’s rep didn’t comment.