While many celebrities were in Tampa, FL to see the Super Bowl on Sunday, actress Jessica Biel stayed in California to give her boyfriend Justin Timberlake the ultimate birthday surprise.

Biel threw the singer a Super Bowl themed surprise birthday party at the Roosevelt Hotel's exclusive penthouse in Hollywood, People magazine reports.

Biel invited 100 of the couple's closest friends including both their parents, her brothers, Timberlake's cousin and his best friend.

To celebrate Timberlake turning 28, the penthouse was surrounded with flat-screen televisions for guests to watch the big game while feasting on gourmet buffalo wings, pizza and red velvet cupcakes.

Biel wore a little black dress and flats to the party -- sources say she planned the festivities down to every detail, visiting the hotel several times.

"They held hands and relaxed," a guest tells People of the couple. "They seemed very happy together."