A man has been attacked with a baseball bat during an attempted armed robbery in the Melbourne suburb of Wantirna South this morning.

Police said the Coles Express service station employee was struck several times to the head and face with the bat after being approached by a customer around 12.10am this morning.

The man had attacked the attendant after asking him for help to find some car oil.

The attendant managed to overpower the man and turn the bat on him, striking him several times also and sending him fleeing south along Stud Road empty-handed.

The service station employee was taken by ambulance to the Maroondah Hospital with a possible broken nose and severe cuts and bruises.

Police are seeking a man described as Caucasian, approximately 5’10" or 177cm tall, of thin/medium build and wearing a light grey hooded windcheater with white ‘PUMA’ writing on the front, dark coloured Adidas tracksuit pants and white runners.