After he walked into the church, he turned to a teen girl in a wheelchair and approached her.
Francis looked down, took the girl's hands and moved his face close to hers.
He then placed his hands on her face and blessed her.
The girl, identified as Stephanie Gabaud, 17, of White Plains, NY, smiled and onlookers in the packed church burst into applause.
"Just to get an actual blessing from him was so amazing," Gabaud told ABC-owned station WABC.
Gabaud, who got to meet Pope Benedict XVI when he was in New York in 2008, suffers from spina bifida, which causes the spinal cord not to develop properly, according to WABC.