The 29-year-old actress presented Hudgens and the Broadway cast of Gigi ahead of their performance of "The Night They Invented Champagne."
Tisdale and the 26-year-old actress co-starred as Sharpay and Gabriella in the Disney High School Musical film series, and remain close friends to this day. Tisdale introduced Hudgens as her "best friend" after taking the stage.
Gigi is based on the 1945 Colette novel and the 1958 film of the same name. Hudgens plays the title character, and co-star Victoria Clark was nominated for Best Featured Actress in a Musical for her portrayal of Mamita.
"We all went through something together that was pretty amazing and life-changing," Tisdale recently told Us Weekly of Hudgens and her other High School Musical co-stars. "We weren't really prepared for all of the things that happened, so it bonded us forever -- we're family."
Tisdale is also known for playing Maddie on The Suite Life of Zack & Cody, and went on to star as Savannah on The CW series Hellcats. She will next portray Danni on TBS sitcom Clipped, which premieres June 16 at 10 p.m. ET.