Exit polls issued immediately after voting ended in the Greek general election indicated that New Democracy was ahead of anti-bailout party, Syriza.
The Washington-based IMF said it was ready to continue lending support to Greece's economic growth and job creation efforts.
The global economic recovery and growth will be the most pressing topics at the G20 summit in Los Cabos, Mexico, on Monday and Tuesday.
Nearly 10 million Greek voters will make their choices in a new parliamentary election, after which the winner will be in talks to form a coalition government.
Spanish Prime Minister Mariano Rajoy said Saturday that Greece should stay in the euro zone.
Greek authorities battled several wildfires burning near Athens and southern Greece on Saturday, on the eve of critical general elections.
Greek private television channel SKAI was targeted with a hand grenade in Athens on Sunday, the general election day that could decide the debt-laden country's future in the euro zone.
French Prime Minister Jean-Marc Ayrault said on Friday that France and Germany should work "hand-in-hand for a solution to pull Europe out of crisis", and called for stronger contacts with Berlin.
German Chancellor Angela Merkel acknowledged on Thursday that Europe's lingering debt crisis will dominate this weekend's summit of the world's 20 most important economies in Mexico, but she stuck to her conviction that the region's crisis can only be solved by keeping a tight rein on government finances and introducing structural reforms.
Greece must stay in the eurozone and maintain close ties with China to overcome the debt crisis, Greek parliament speaker Vyron Polydoras said.
Greek banks are facing massive withdrawals as depositors fear that the general election, scheduled for Sunday, will lead to a failure in forming a new government and further fears of Greece exiting the eurozone, said a senior banker.
Group of 20 leaders meeting in Mexico next week to discuss the state of the global economy should not focus exclusively on problems in the euro zone.