The Brit was performing at the Hollywood Bowl when he surprised the crowd by bringing out Cusack, who appeared with the famous boombox in hand.
He presented it to the rocker, who recreated the famous scene by holding the boombox above his head - like Cusack's character Lloyd Dobler does in the film when he plays Gabriel's love song In Your Eyes while trying to woo his crush.
Gabriel also gave a shout-out to Say Anything... director Cameron Crowe, who was in the audience and later tweeted, "Peter Gabriel and John Cusack on stage (at the) Hollywood Bowl tonight. Won't forget that... ever."
Cusack replied, "And I will never forget Cameron... If I were u (sic) I would follow Cameron Crowe and occasionally suggest we work together again - was so happy to see him last night at Gabriel."