Ansel Elgort sent fans into overdrive on Sunday (23Jul17) when he made a surprise appearance at a screening of his new film Baby Driver in Brazil.

The Fault in Our Stars actor shared footage of the surprise on Instagram, explaining he went incognito in a hooded sweatshirt to keep his identity hidden as movie-goers filed into the theater.

As part of the stunt, a cinema official staged a fake competition after the screening to give one lucky person the chance to meet Elgort, after which his presence was announced.

"So fun!!! Surprising this theater in Brazil showing a screening of #BabyDriver!!!," he captioned the video clip.

"I sat in the audience in this hoodie, nobody knew it was me then the woman on the mic asked for a volunteer to pick a name out of a hat that would get a special meet and greet with 'Ansel' and I raised my hand. To come pick a winner."

The stunt didn't quite go to plan, but Elgort had a blast regardless.

"Unfortunately she yelled my name before I made it down (the stairs) to surprise everyone but it was still epic!," he continued. "After this we all took pics together! Instead of one winner there were 200!"

He added, "Loved meeting you guys and watching the movie w (with) you too! I was so nervous somebody would notice me and distract everyone watching the movie for the first time! Can't wait for everyone to see Baby Driver".

Elgort was accompanied on the press trip by his longtime girlfriend Violetta Komyshan.

The actor portrays the titular getaway driver Baby in the ensemble heist film, which was directed by Edgar Wright and also stars Kevin Spacey, Jamie Foxx, and Jon Hamm.