That followed the start of the first ore processing campaign at the Lakewood mill on July 17.
Unreconciled mill grades to date have been largely in line with expectations.
A formal grade reconciliation update will be provided when the first mill campaign is complete.
Monthly mill campaigns have been scheduled through to January to treat 159,000t of ore grading 1.8 grams per tonne gold.
Horizon managing director Jon Price said first gold production from Boorara was an exciting milestone for the company.
Dore bullion will be shipped to the Perth Mint for refining and sale with first revenue expected in coming weeks.
The first gold pour came just as gold was nearing an eight-year high of US$1900 an ounce.
Shares in Horizon dropped 3.4% to A14c, valuing the company at $63.4 million.
