The accused, identified as Vikram, was in an inebriated condition when the incident took place last night, and was nabbed by a constable who was present at the spot.
Vikram works at a printing press in Civil Lines and resides in Sabzi Mandi area.
The woman is a student at a private university here.
"The incident was reported to police around 10 PM. The victim had gone to buy vegetables in the market when the man caught her from behind," a police official said.
"A case under section 354 IPC (outraging the modesty of a woman) has been registered at Sabzi Mandi police station," said Deputy Commissioner of Police (North) Madhur Verma.
Vikram was produced before the court today and has been sent to judicial custody.