CPD responded to the fight about 2:45 a.m. in the 3200-block of North Halsted Street, near Belmont Avenue.
The male officer injured his back while trying to place a suspect into custody, Chicago police said.
RELATED: Chicago Pride Fest kicks off with heightened security following foiled white nationalist plot
He was taken to Advocate Illinois Masonic Medical Center in fair condition, and the suspect was taken into custody.
No other injuries were reported, CPD said.
Chicago's Pride Fest returned to the North Halsted corridor this weekend, bringing large crowds and heightened security after a foiled attempt by white nationalists to disrupt a pride event in northern Idaho.