"The Late Show" host David Letterman paid a touching tribute to late actor Robin Williams on Monday night's episode of his talk show.

Williams, who passed away on August 11 after allegedly taking his own life, was remembered by thousands of celebrities in the United States and other parts of the world.

But when it was time for Letterman to pay his respects to his good friend, the result of his touching video brought tears to his audiences' eyes.

In the tribute, Letterman recounted the first time he met Williams nearly four decades ago while they were both up against each other as amateur comedians and competitors at the Comedy Store in Hollywood, according to Slate.

The ten-minute video saw Letterman gushing over Williams as a comedian and as a person when he said, "All of a sudden he comes up on the stage and - you know what it is - it's like nothing we had ever seen before, nothing we had ever imagined before."

"And then he finishes and I thought, 'Oh that's it, they're gonna have to put an end to show business because what could happen after this?' Honest to God, you thought, 'Holy crap, there goes my chance in show business because of this guy,'" Letterman said.

Years after their first meet-up, Letterman recounted the time when Williams himself invited him to guest star on "Mork & Mindy," Aceshowbiz reported.

"Even to the detriment of the show, Robin was kind enough to invite me to come on because he thought, 'Why can't I spread this around and have some of my friends share in my success?' Which is exactly what he did.'"

Williams, who appeared on Letterman's talk show for at least 50 times, was a force to be reckoned with. During his appearances, Letterman revealed that only one of two things would always happen, Boston Herald noted.

"One, I didn't have to do anything. All I had to do was sit there and watch the machine. And two, people would watch. If they knew Robin was on this show the viewership would go up because they wanted to see Robin," he revealed.