Tennis U.S. Open Champion Novak Djokovic Serves Balls at 'Late Show' Host Stephen Colbert

It's officially the second week of The Late Show with Stephen Colbert, and the former Report host decided to kick it off by having U.S. Open tennis champ Novak Djokovic serve tennis balls at his head.

Yep, really.

During Monday night's monologue, Colbert brought out the champ, alongside his trophy, and delivered a quick Q&A. Colbert called the battle at the U.S. "epic" and offered up a heavy congrats to the star. "In fact, let's do it right now," he said.

After some talk about what it's like being the U.S. Open champion, and what perks come with the position – like free refills at the movie theater, which is great considering they're upwards of $50 now – Colbert told Djokovic to tell the crowd of another prize.

"Today, I get to serve tennis balls at you," he said. Luckily Colbert had Captain America's shield to protect him.

"This, folks- it's a time-honored tradition," he claimed, and proceeded to prepare himself for the serves. Which, by the way, apparently have topped out at 130mph.

And... that's just terrifying.

Now, we're not sure if Colbert was joking with that shriek but he seemed to continue the show without a problem.

 A moment of calm before the storm... #2015usopen

A photo posted by Novak Djokovic (@djokernole) on Aug 29, 2015 at 5:23pm PDT

Also on Monday night's episode of The Late Show was actress Emily Blunt, United States Supreme Court Justice Stephen Breyer and musical guest The Dead Weather, which is a supergroup comprised of Alison Mosshart, Jack White, Dean Fertita and Jack Lawrence.

Be sure to check out Colbert's impromptu duet with Blunt because – It. Was. Wonderful.

A photo posted by Late Show with Stephen Colbert (@colbertlateshow) on Aug 27, 2015 at 7:45pm PDT