Syriza to win Greek election

Official results from 54.2 percent of polling stations counted showed Syriza with 35.9 percent and prime minister Antonis Samaras' centre-right New Democracy with 28.3 percent, reports AP.

"Today we have celebration, tomorrow we start to work hard," said Tsipras, speaking after Samaras officially conceded defeat.

"Today was a defeat for the Greece of the elites and the oligarchs. We regain hope, optimism and dignity", he added.

"Greece is leaving behind the austerity that led to destruction. The verdict of the people makes the troika history in our common European framework," he said referring to the European commission, ECB and IMF representatives who oversaw the country's reform programme.

Syriza's spectacular rise to power has come on the back of the harsh price Greeks have had to pay for their international bailouts, resulting in tax hikes, wage cuts, slashes in public spending, and an unemployment rate of about 50 percent among young people.

Tsipras originally said he wanted to tear up the terms of the country's bailouts, but modified his language in the run-up to Sunday's vote to say that he wants to renegotiate Greece's debt.

It is unclear whether Syriza has won enough to govern outright or if it needs to form a coalition.

The Greek election is being closely followed around Europe, particularly in fiscally hawkish countries such as Germany.

"Any new government must stick to the contractual agreements of its predecessors," said German finance minister Wolfgang Schaeuble at the end of December.

An updated version of this message was delivered by Bundesbank chief Jens Weidmann on Sunday evening.

"I hope the new government won't call into question what is expected and what has already been achieved," he told public broadcaster ARD.

Meanwhile, a Syriza victory may inspire radical left parties elsewhere - Spain is due elections this year and, as in Greece, its traditional centrist parties have been challenged by the rise of a leftist party, Podemos.