Group gold production was 98,547 ounces of gold, keeping the miner comfortably on course to meet its FY19 forecast of 350,000-375,000oz, but below the outstanding June quarter result of 119,436oz.
The flagship Gwalia mine in Western Australia produced 62,685oz of gold, with the average grade dropping to 11.8 grams per tonne gold from 13.2gpt, but remaining well over the reserve grade of 7.5gpt.
The performance is in line with Gwalia's full-year guidance of 245,000-260,000oz.
Simberi, in Papua New Guinea, delivered its best quarter this calendar year with 35,862oz produced.
The result was due to a higher milled grade of 1.48gpt, up from 1.45gpt, and recoveries of 86%.
FY19 guidance of 105,000-115,000oz was maintained.
Full details and cost performance will be released on October 17.
St Barbara's cash balance rose by $7 million to A$350 million after the payment of $28 million of dividends, $6 million in tax and a further $3 million investment in Peel Mining.
"Both operations continue to perform well, with the strong cash balance of $350 million positioning the company to deliver on our organic growth projects and consider inorganic opportunities," St Barbara managing director and CEO Bob Vassie said.
Macquarie said the result laid the foundation for another strong year for St Barbara, with September quarter production putting the company at an annualised run-rate of 394,000oz.
"We note that we had anticipated 1QFY19 to be St Barbara's strongest, with Gwalia's grade expected to soften over FY19 and ore volumes to be affected by raise boring activities," it said.
"Simberi's strength is a highlight and supports our view that the sulphide project at the mine is becoming increasingly likely."
Macquarie retained an outperform rating and $4.50 price target.
Canaccord Genuity yesterday upgraded St Barbara to buy from hold, with a price target of $4.40, up slightly from $4.35.
St Barbara shares closed at $3.48 yesterday, valuing the company at more than $1.8 billion.