A Good Samaritan has been left bleeding from the head after a racist thug turned on her when she tried to defend a woman of Indian appearance being abused at a Melbourne supermarket.

Simone Wiebenga was at a Preston Coles self-service checkout on January 6 when she heard a man unleash a racist tirade on the innocent woman.

"He was calling her a f-----g black c--t, a black dog, and saying what are you doing here," Ms Wiebenga told 9NEWS.

Simone intervened as the thug hurled racial abuse at a woman of Indian appearance. (Supplied)

The thug turned on her and threw supermarket objects at her head. (Supplied)

That's when she intervened and asked the man to leave the woman alone.

But then he turned on her.

He abused Ms Wiebenga before throwing supermarket items at her head.

Simone, who is on blood thinners, was left bleeding from the head. (Supplied)

"I just could not stand the way he was treating her," she said.

"She was a tiny girl, he was a big bloke, imposing, using his body to bully and intimidate."

Simone, who has a heart condition, was bleeding from the head as customers ran to her aid.

"Having a heart condition, because of blood thinners, blood was everywhere."

"I just could not stand the way he was treating her," Simone told 9NEWS.

The thug left the Coles at Northland Shopping Centre shortly after 7:30am. (9NEWS)

The woman thanked her for standing up to the man before police and paramedics arrived.

Police are now hunting for the man responsible for the racial attack who then assaulted Simone.

He left the Coles at Northland Shopping Centre shortly after 7:30am.

Police say the offender was last seen walking towards Murray Rd from Northland Shopping Centre. (9NEWS)

Simone has spoken about the ordeal in the hope that he is caught. She is concerned that he will do something similar again, and that he may become more violent.