The crime happened at about 8:02 p.m. at the store located at 814 Higgins Road, Park Ridge police said.
Police said the two suspects entered the store, walked around the counter and maced the clerk.
The suspects allegedly took several cartons of cigarettes and bottles of liquor.
They were last seen on foot heading south on Cumberland Avenue, police said.
The clerk was taken to the hospital. He is expected to be OK.
Park Ridge police said the suspects were described to be men dressed as women. One was wearing a black shirt and grey pants. The other was wearing a tan shirt and black pants.
Police said both suspects were wearing bandanas on their heads.
No other information was available.
Last year, A family was carjacked while out to buy milk at the same gas station.
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