The Cannes Film Festival was being held just down the road, drawing a slew of celebrities.
But the two actors appeared to have jetted in to the royal principality just for the race.
The 33-year-old actor shared several images on Instagram showing him with “The Martian” star.
“Great trip to Monaco thanks to @tagheuer #formula1,” Hemsworth wrote in a caption to the photos. He was obviously traveling on someone else’s dime. Ah, the perks of being a celebrity.
One image showed him with his wife on a boat. Damon was visible in the background “#MonacoGP@tagheuer #formula1 #yakidding!!!!!” he wrote in the caption.
Chris,who has sons Tristan and Sasha, three, as well as five-year-old daughter India with his wife, was also joined by his assistant Aaron Grist.
Captioning a picture of Chris and Aaron posing side by side, it read: “In Monaco with all round nice guy @azzagrist. Thanks to@tagheuer. #dontcrackunderpressure#formula1 #sponsored #monacoGP.”
Elsa also posted an image on the photo-sharing site to gush about how much “fun” they had.
A sweet picture of the pair together was captioned: “Los buenos momentos!! Fun times!! @tagheuer #grandprixmonaco #justus#greatweekend #monacograndprix.”
Hemsworth and Damon are pretty tight pals. They also traveled together to Australia, Chris’s home country, for a vacation earlier this year.