(ATHENS, Greece) — A radical left-wing party that is demanding an end to Greece’s painful austerity measures won Sunday’s parliamentary elections, threatening renewed turmoil in global markets and throwing the country’s continued membership in the eurozone into question. But Syriza, which is led by 40-year-old Alexis Tsipras, was still waiting to find out whether it would have enough seats to govern alone, or be forced to seek support from another party, either in a coalition or as a minority government.