Spears opened the 2008 event with a comedy segment in which "Superbad" actor Jonah Hill pretended to attempt to teach her relaxation techniques in her dressing room and tried several times to kiss her before ending their "romantic relationship."

A moment later, Spears appeared on stage looking fit and happy, clad in a sparkly, silver, low-cut, fringed dress and glittery, high-heeled sandals.

"Thank you for all the love," she said as she received a standing ovation. "I'm here tonight to celebrate a very important birthday -- the 25th anniversary of the VMAs. This is the 2008 Video Music Awards and it starts right now."

Rihanna then performed her hit song "Disturbia."

Afterward, Spears picked up the evening's first award -- the moon man for Best Female Video for her song "Piece of Me."

"I first want to thank God, first and foremost, for just blessing me like this, my beautiful family, my two beautiful boys for inspiring me every day and my fans -- this is for you," she said. "Thank you so much."

Spears -- who had not won a VMA before this year -- also won the awards for Video of the Year and Best Pop Video.