He was voted through Friday's night's semi-final with the Missing people Choir.
The choir, made up of relatives and friends of people who have gone missing, and backed by Kate McCann, are the long-running favourites in the competition, but came second in the semi-final behind Chaponda.
The group includes the sister of missing Manic Street Preachers guitarist Richey Edwards, the father of chef Claudia Lawrence, and Peter Boxell and Denise Horvath-Allan, whose children have both been missing for 28 years.
Earlier, judge Simon Cowell had said he was "rooting" for the choir but added there was a "lot of expectation" on them.
During their moving semi-final performance, photos of dozens of missing people were shown above the stage while the audience held white lights in the air.
The group were formed by the Missing People charity and their first audition, which brought the judges to tears, was a performance of I Miss You, a song penned by Boxell which also includes lyrics written by schoolgirl Alice Gross, who was murdered in 2014 aged 14.
Peter Lawrence has frequently spoken to Premier about his Christian faith and how it has helped him cope following the disappearance of daughter Claudia.