'Game of Thrones' star celebrates Jimmy Fallon's 1,500th episode in the most epic way

There's no doubt we should still be "bending the knee" to Kit Harington, aka the King in the North Jon Snow, who helped The Tonight Show Starring Jimmy Fallon celebrate its 1,500th episode Thursday by doing what host Jimmy Fallon said celebrities have "passed on" for years.

"Guys, tonight is our 1,500th show and, in honor of that, something special is about to happen," explained Fallon. "Years ago we had an idea for a bit called 'Straight Up Goes for It.' It was a simple idea. We wanted somebody to come out and straight up sing 'Drops of Jupiter' by the band Train. That's it. That's the whole idea."

"The sketch has been our white whale," Fallon added. "We've been pitching it for years. Dozens of people. Famous people that you know and love, both singers, they sing in movies, they dance and they sing, and they actually have music out. They all passed on it. But not tonight. Tonight that changes, because we finally have someone who has the guts to do it."

That person was Kit Harington and, well, he straight up went for it.

Harington doesn't know how to play the piano at all. In fact, Fallon said he doesn't even really know how to sing, which made the performance even more epic. And later in the show, Harington revealed why he decided to "go for it," even though a large part of his brain was telling him not to.

"I had a lot of thoughts when you sent me that. Like, a lot," Harington admitted to Fallon. "And the sensible part of my brain, the bit that said, 'You're not a singer, you have no connection to this song, it's of no relevance to anything you're talking about on the show,' said don't do it. But there was another little part of my brain, right? The bit that gets me in trouble, that was like, 'But what if you're brilliant?'"

Harington said that he thought there was a chance that his performance might "open up whole new vistas of a career in singing." However, he also admitted that in the ten seconds before he started the performance, "that same little part of my brain said, 'you shouldn't have done this.'"

The Tonight Show Starring Jimmy Fallon airs weeknights at 11:35 p.m. on NBC.

Watch Simon Cowell breaking down while speaking to 'AGT' contestant who quit due to cancer:

Read more from Yahoo Entertainment:

• Billy Crystal reveals he got high before getting an MRI during recent health scare

• 'Jeopardy!' champion officially becomes third-highest winner in the history of the show

• Barbra Streisand reveals the stage name she could have had

Tell us what you think! Hit us up on Twitter, Facebook or Instagram. And check out our host, Kylie Mar, on Twitter, Facebook or Instagram.