The rate was the lowest recorded since Q4 in 2012, when unemployment reached 26.2 percent.
About 74.4 percent of Greece's 1.28 million jobless are long-term unemployed, meaning they have been out of work for at least 12 months, the figures showed.
Greece has already published monthly unemployment figures through June, which differ from quarterly data because they are based on different samples. Quarterly figures are not seasonally adjusted.
Hit hard by austerity policies, Greece's annual average unemployment rate reached 27.3 percent in 2013 from 24.2 percent in the previous year.