Greece's state statistics agency on Friday drastically revised downwards the economy's third-quarter contraction to 0.9 percent, from 0.5 percent previously.
"These differences are on account of using new data, not available at the time of the flash estimate," the Elstat agency said, citing a mixture of September balance of payments data, service turnover and jobless figures as factors for the downturn.
In an annual comparison, Greek output fell by 1.1 percent from the third quarter of 2014, Elstat said.
The flash estimate on November 13 had pointed to a 0.4-percent drop from last year.
The data is consistent with European Commission forecasts that Greece will fall back into recession in 2015 after a brief respite last year.
The Commission is banking on a 1.4-percent contraction in 2015 and a further drop of 1.3 percent in 2016.
Greece's own 2016 budget, to be approved by parliament in early December, foresees "near zero" growth in 2015 and a 0.7-percent economic downturn next year.
Although Greece had a record tourism year, the gains were lost to economic uncertainty as the leftist government of Alexis Tsipras clashed with international creditors in June and imposed capital controls.