Justin Timberlake & Jessica BielJessica Biel threw a surprise birthday party for Justin Timberlake on Sunday afternoon.

Jessica invited around 100 friends and family to the party in the penthouse suite at the Roosevelt Hotel in Hollywood for the Superbowl-themed celebration.

According to onlookers, guests dined on buffalo wings, pizza and red velvet cupcakes while watching the big game between the Arizona Cardinals and Pittsburgh Steelers on flat-screen TVs installed for the occasion.

A guest told People magazine: “Justin was totally blown away when he walked in. He had no idea.

“They held hands and relaxed. They seemed very happy together.”

Justin turned 28 on Saturday. Justin and Jessica began dating around two years ago but only confirmed their relationship at the end of 2007.