The 17-year-old midfielder only made his debut in senior football against Kilmarnock earlier this month.
But he came off the bench and scored in the 5-1 demolition of Partick at Firhill last night as the Hoops finally sewed up the SPFL Premiership.
Henderson said: "Obviously, it has been a great week for me and I am absolutely delighted to be scoring.
"I didn't even see my goal hit the back of the net. I was away before it did so. It was one of the best moments of my life.
"All the boys were delighted I had scored as well. It was a surreal moment - especially to do it on the night we clinched the title.
"The boys have been working hard for this all season. I have only come in for three games. There is no need for me to get carried away.
"I just need to keep working hard. I have been lucky. All the credit goes to the boys who have been working hard for the team for the whole season.
"My phone has been ringing red hot ever since. I have received text messages from my family and my friends. I am glad I have made them proud.
"But I just need to keep working hard. Hopefully this will continue."