Phase two works at Zone 23 and Adit 5 included a 1,200m trenching programme and four widely-spaced drill holes, with a highlight including 32.1m at 1.61g/t from 48.55m before the hole was stopped for technical reasons.
Exploration director Alexander Yakubchuk said the cluster structurally represented an offset from Sun Gold Mining's Klyuchevskoe gold deposit to the east.
He said the Zone 23 results broadly confirmed historical drilling and described the style of mineralisation as intrusion-hosted gold.
Orsu took 30% of Sergeevskoe in May and earlier this month struck a long-awaited deal to acquire a further 60% after selling its Kazakhstan project for less than expected.
It has been exploring at the project since November 2016 and said more drilling would continue this quarter.
Shares in the company closed up 10.4% yesterday to C$0.27 (US$0.21).
