The rocker took the stage in Las Vegas, Nevada last Saturday (16Nov13), and made a special call to fan and concert photographer Andrew Youssef, who is battling colon cancer.
Youssef was told by doctors in September (13) that he only had a few months to live and he was too sick to attend the gig.
Reznor, who had struck up a friendship with Youssef via Twitter.com hit Twitter.com just before the concert and wrote a special message to his dedicated fan.
He wrote, "Tonight's show goes out to our Friend @Amateurchemist (Youssef). Wish you were here, man."
Just before his encore song, Reznor grabbed his iPhone and called Youssef. He then proceeded to dedicate the track In the Twilight to his devoted follower, who watched from his hospital bed.
After the gig, Youssef took to the microblogging site to show his gratitude and wrote, "I'm speechless. Hope to see you @trent_reznor @nineinchnails soon."