Ansel Elgort surprised fans in Brazil at a screening of 'Baby Driver'.

The 23-year-old actor stars in the crime thriller movie as the titular character Baby, and shocked an audience of unsuspecting fans in São Paulo when he snuck into a movie theatre wearing a hooded jacket and watched the movie undetected.

At the end of the movie, Ansel revealed his true identity and the stunned fans were able to take photos with the star, who dubbed the experience as ''epic''.

Taking to Instagram to post a video of the moment he pulled down the hood on his jacket in front of the cinema-goers, Ansel wrote: ''So fun!!! Surprising this theatre in Brazil showing a screening of #BabyDriver!!!

''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.

''Unfortunately she yelled my name before I made it down to surprise everyone but it was still epic! After this we all took pics together! Instead of one winner there were 200! Loved meeting you guys and watching the movie w 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 :) (sic)''

'The Fault in Our Stars' actor also posted a photo of himself sat in the theatre seats surrounded by fans.

The snap was captioned: ''SURPRISING AN AUDIENCE OF #BABYDRIVER IN BRAZIL!!! ([photo by]- @carmelovarela ) (sic)''

Meanwhile, Ansel previously claimed he thought he was ''super easy to hate'' simply because he is successful.

He said: ''I don't walk around calling attention to myself. It's important to be able to blend in; otherwise you turn into a Hollywood douche bag.

''I'm sure plenty of people think I am one, too. I'm super easy to hate. But it's fine. It's hard to be liked and successful.''