Woolworths Caltex Dubbo was the first ever petrol station opened by the supermarket chain in Australia, and to celebrate their 20^th anniversary unleaded and diesel petrol were 64.9 cents per litre. E10 hit 62.9 cents.

At 2.15pm, the price of unleaded petrol was no longer 128.9 cents, and diesel wasn’t 119.9 cents.

It was a shock for customers like Tracey Johnston, who said it normally cost her between $90 and $100 to fill her tank.

Ms Johnston said she had only called into the petrol station for a small top up, but had to fill her tank completely when she saw the birthday special.

Within moments a line of eager motorists had formed at the petrol station, looking to cash in on the cheap deal.

Woolworths Fuel and Metro acting managing director Angus Armstrong congratulated some of the long serving staff at the depot for both their service to the company and their safety record at the petrol station.