Alexis Tsipras, head of the left-wing Syriza party which won Greece's parliamentary election for the second time this year on Sunday, says he will form a coalition government with the small right-wing Independent Greeks.
Speaking before thousands of jubilant supporters in central Athens, Mr Tsipras said he was joining forces once again with Panos Kammenos, the junior coalition partner with whom he governed from January until last month.
Mr Kammenos joined him on stage to rapturous applause from the crowd.
With 61% of the vote counted, Syriza had 35.5% of the vote and 145 seats in the 300-member parliament, while the Independent Greeks were in seventh place with 3.6% and 10 seats.
The conservative New Democracy was in second place with 28.2%.
The result was a resounding success for Mr Tsipras' high-risk gamble when he resigned last month and triggered early elections, barely seven months into his four-year term, in order to face down a rebellion within Syriza over his policy U-turn to accept painful austerity measures in return for Greece's third international bailout.