Flame, real name Marcus Tyrone Gray, accused Perry of copying the beat from his 2009 song, Joyful Noise, featuring Lecrae, in her 2013 hit Dark Horse.
Perry, who started out as a Christian music artist before going mainstream, appeared in court during the trial to give evidence and claimed that she had never heard of the track or the artists before making her own song.
Giving evidence during the trial, Christian rapper Da Truth, real name Emmanuel Lambert Jr, dismissed this idea, telling the court that Joyful Noise had been a big hit in the Christian market and could have been heard by Perry on online streaming platforms.
In his complaint, Flame said that the beat from Joyful Noise had been used without permission.
"Defendants never sought or obtained permission from plaintiffs to use the 'Joyful Noise' song in creating, reproducing, recording, distributing, selling, or publicly performing defendants' song," the complaint reads.
"Plaintiffs never gave any of the defendants permission, consent, or a license to use 'Joyful Noise' for any purpose, including creation of a derivative work based on 'Joyful Noise'."
Perry's legal team tried to argue that there was no copyright claim to be made because the beat in both songs were "commonplace".
Earlier in the trial, musicologist Todd Decker said he had identified "five or six points of similarity" between the two songs.
The court has ruled that all six artists who contributed to Dark Horse are liable, including Perry and rapper Juicy J, who contributed a verse.
It has not yet set the amount of damages to be awarded to Mr Gray.