Marc Malkin

AP Photo/Chris Park

George Michael showed off more than just his voice last night during the opening show of his new 25 Live tour.

"You could tell he wasn't wearing underwear," reports a concert-goer at the San Diego Sports Arena. "It was flopping all over the place."

Manhood aside, the source raved that the concert was like nothing he had ever seen before.

"Everything from the his voice, to the lighting, to the stage was beyond anything I have ever experienced," he said.

The two-and-a-half-hour show included about 20 songs, three costume changes, six backup singers and a production that reportedly cost upwards of $2 million to put together.

Before dedicating the ballad, "Amazing," to his partner, Kenny Goss, the 44-year-old former Wham! heartthrob acknowledged California's recent legalization of gay marriage. "He said, 'I was watching TV yesterday and saw two women get married,'" the source says. "The crowd went crazy."

They also went crazy for clips from Michael's vintage music videos, especially 1992's "Too Funky," which featured a slew of supermodels. Another video created just for the show and played during Michael's cover of "Feeling Good" featured Dita Von Teese stripping down to nothing but pasties and her undies.

At the end of the night, Michael more than thanked his fans. "He was so humble," the source says. "He got down his knees, and he was bowing to the crowd."

The 25 Live tour is Michael's first North American tour in 17 years.