A phone thief sexually assaulted a woman near Millennium Park on Tuesday after she chased him from a CTA Red Line station in the Loop.

The 27-year-old had just gotten off a Red Line train near State and Lake streets between 3 and 3:40 a.m. when a male suspect grabbed her phone and took off, according to Chicago police.

She chased him to the 100 block of East Randolph Street, where he sexually assaulted her, police said. The suspect then ran away.

The woman was taken to Northwestern Memorial Hospital, where her condition was stabilized, police said.

The suspect is described as 25 to 35 years old with long black dreads, police said. He was wearing a red and black hat, black T-shirt, black pants, black shoes and a dark multicolored backpack.

No one is in custody as Area Central detectives investigate.

Read more on crime, and track the city’s homicides.