Hayden Panettiere celebrated her 21st birthday all over again on Friday - partying with pals in New York.

The actress reached the milestone on Aug. 21 and marked the occasion with a spectacular bash on the Detroit, Michigan set of her new movie Scream 4 - complete with fireworks and a three-foot dolphin birthday cake.

But Panettiere wasn't satisfied with the festivities and jetted back to her native New York this weekend so she could enjoy a more low-key birthday bash with old friends.

The star was spotted feasting on tacos and burritos and downing cheap cocktails and shots with eight pals at Mexican restaurant Blockheads in Manhattan on Friday night.

A fellow diner tells WENN, "It wasn't a very showbizzy gathering and Blockheads isn't exactly a celebrity hang-out. But Hayden looked like she was having a great time. The party was pretty rowdy, with lots of laughing and joking. But nobody minded. She was even treated to a rendition of Happy Birthday by all the waiters, who brought her out some cake. Everyone in the restaurant joined in."

There was one conspicuous absentee - Panettiere's giant boxer beau Wladimir Klitschko. The onlooker adds, "She did look like she was missing her boyfriend. She was on her iPhone every five minutes, checking for messages from him."