Dwayne Johnson arrives at Comic-Con in full costume to promote Black Adam

Fans were treated to an extended look at the film.

Dwayne Johnson appeared in full superhero costume – surrounded by crackling electricity and swirling smoke – to promote upcoming DC blockbuster Black Adam at Comic-Con in San Diego.

The Hollywood star made an epic entrance onstage at the famous Hall H and warned fans that the superhero universe would “never be the same again”.

Blue sparks flew in the darkness as special lanyards given to attendees flashed blue ahead of the second panel of the day on the third day of the world famous convention.

“Hall H you have been warned the DC universe will never be the same again,” he declared.

Fans were treated to an extended look at the film with explosive footage showing Johnson deflecting bullets and smashing helicopters into each other.

“I heard Black Adam was here, that was some cool s***,” Johnson joked as he returned to the stage alongside his fellow cast members Aldis Hodge, Noah Centineo, Quintessa Swindell and director Jaume Collet-Serra.

Johnson told fans that fellow cast-member Pierce Brosnan sent his love, but was unable to attend the convention.

“The journey for Black Adam has been long and filled with passion, with commitment and grit. It’s been easily 10 years,” he said.

“The journey has been an incredible one.

“To be here to watch Black Adam levitate and throw lightning like he was handing out candy, it’s a dream come true.”

Collet-Serra admitted that he was “shy” and that the panel was his “worst nightmare”.

The film is scheduled for a UK release of October 21.

Moments before, fans were officially introduced to the “Shazam-ily” as a new trailer for the superhero sequel Shazam! Fury Of The Gods debuted.

Stars of the film Zachary Levi, Asher Angel and Jack Dylan Grazer appeared on stage on the first panel of the day, and virtual messages were sent by Dame Helen Mirren and Rachel Zegler, who could not attend.

Dame Helen Mirren joked that she had been banned from Comic-Con for fighting, and shocked fans with a humorous but risque greeting.

Other panels teed up for Saturday include HBO’s House Of The Dragon and a Marvel “mega-panel”.