Athens (AFP) - Outgoing Greek prime minister Antonis Samaras has conceded defeat in Sunday's general elections, the victorious anti-austerity Syriza party said.Samaras telephoned to congratulate 40-year-old Syriza leader Alexis Tsipras, who responded that "there is joy and sorrow in politics," Tsipras' office told AFP.Join the conversation about this story »