Support fell away from incumbent leftist Prime Minister Alexis Tsipras' Syriza party, while it looks like extreme right-wing party Golden Dawn failed to win even one parliamentary seat.
Greece's new prime minister, Kyriakos Mitsotakis, formally takes up the reins, a day after an election victory that puts him in charge of the EU's most indebted member with promises to end a decade of economic crisis.
The challenge facing the US- and UK-educated conservative is a hefty one as he takes over from defeated leftwing leader Alexis Tsipras, who imposed austerity measures required under a bailout to keep Greece in the eurozone.
The country's public debt last year stood at 335 billion euros ($376 billion), or 180 percent of GDP.
The debt load is forecast to fall to 168 percent of GDP this year, but only under belt-tightening brought in under Tsipras's Syriza party -- something that Mitsotakis's New Democracy party says is stifling growth.
The tricky job of keeping Greece's international creditors onside while easing the hardship on Greeks -- by lowering taxes and renegotiating fiscal targets -- could result in a short honeymoon phase for Mitsotakis.
Official results from 94 percent of polling stations showed New Democracy scored a crushing victory by nearly 40 percent -- its best score in over a decade -- to 31.5 percent for Tsipras's leftist Syriza party.
If the results are confirmed, the 51-year-old Harvard graduate and former McKinsey consultant Mitsotakis will have a majority of 158 lawmakers in the 300-seat parliament. Tsipras's party will have 86 seats.
The final number will depend on how smaller parties fare. They need at least 3.0 percent of the vote to enter parliament.
'Message for change'
The 51-year-old Harvard graduate and former McKinsey consultant has pledged to create jobs and get rid of obstacles to business.
Those pledges wooed Greek voters, who handed him 40 percent of the votes in Sunday's election, well ahead of the 31.5 percent given to Tsipras.
"It's a strong message for change in Greece," Mitsotakis declared to the channel CNBC.
Last week he told AFP that he saw it as his mission "to make sure we restart the economy" with "ambitious growth driven by private investments, exports and innovation".
He predicted that he could persuade Greece's creditors to accept the easing of tight fiscal targets if "a comprehensive reforms package" was presented.
Tsipras, for his part, warned that Mitsotakis would do away with the social spending he brought in to help Greece's vulnerable groups.
He portrayed the Mitsotakis family -- one of Greece's leading political dynasties -- as part of a failed system that bankrupted the country in 2010, creating the need for the humiliating bailout.
Son of a PM
Mitsotakis is the son of former prime minister Constantine Mitsotakis, one of the country's longest-serving parliamentarians. His sister, Dora Bakoyannis is a former minister and Athens' first female mayor.
He took charge of the New Democrats three years ago. Following the election, his party will have a majority of 158 seats in the 300-member parliament.
New Democracy was last in power in 2014, in coalition with the Greek socialists.
Syriza's parliamentary presence will shrink from 144 seats to 86. Tsipras has promised to remain an "active" voice in opposition.
Sunday's election was Greece's third in as many months.
In May, New Democracy beat Syriza by nearly 9.5 points in European parliament elections. A week later, it completed a near-sweep of Greek regions in local elections. After that, Tsipras was forced to call an early general election.
"A painful cycle has closed," Mitsotakis said in a televised address immediately following his electoral victory, adding that Greece would "proudly raise its head again" on his watch.
The new smaller parties fighting to secure representation are Greek Solution, a nationalist party formed by TV salesman Kyriakos Velopoulos, and MeRA25, an anti-austerity party founded by maverick economist and former Greek finance minister Yanis Varoufakis.
According to the exit polls, Varoufakis's party could elect nine lawmakers.
Greek Solution could end up with 10 deputies, while neo-Nazi party Golden Dawn looks likely to be shut out of parliament for the first time since 2012.
Golden Dawn, until recently Greece's third-ranking party, is in steep decline amid an ongoing trial for the 2013 murder of an anti-fascist rapper, allegedly carried out with the knowledge of senior Golden Dawn members.
Mitsotakis has promised to hit the ground running. A Eurogroup finance meeting on Monday will convene to discuss the state of Greece's economy after tax cuts rolled out by Tsipras in May.