A man was approached by two people who unleashed a spray before stabbing him late Tuesday in the Gresham neighborhood on the South Side.

At 11:30 p.m., the 51-year-old was walking near the intersection of 84th Street and Halsted Street when a male and a female approached him, according to a statement from Chicago police.

The female sprayed him with an unknown substance, police said. The male then stabbed him in the lower back.

The 51-year-old was taken to University of Chicago Medical Center, where his condition was stabilized, police said.

Area South detectives were investigating.