Greece's Prime Minister Kyriakos Mitsotakis promised "big reforms" on Monday as he began a new four-year term following a resounding election win.
Mr Mitsotakis guided Greece's conservative New Democracy party to its biggest win in years after campaigning on an economic turnaround from the 2010s financial crisis.
It was the second election in weeks after a May vote showed strong support for Mr Mitsotakis but left him short of a majority.
After gaining a majority on Sunday, he was formally sworn in for another term by President Katerina Sakellaropoulou.
Mr Mitsotakis said his government would "put in place major changes" during his second term, having promised to invest in healthcare and improve railway safety after a collision in February killed 57 people.
He has also pledged to to push ahead with reforms to rebuild Greece's credit rating after the debt crisis, and to boost revenue from the vital tourism industry.
"We will begin working hard for big reforms," he told the president after re-assuming power.
Harvard-educated Mr Mitsotakis declined to form a government after May's election, instead gambling that he could win a majority in a re-run once a new voting system took effect.
The gamble paid off, as New Democracy took 158 seats in the 300-member parliament, with left-wing Syriza far behind on 48.
Mr Mitsotakis remains popular despite the rail disaster and a wiretapping scandal involving senior politicians and journalists.
Syriza's leader, former prime minister Alexis Tsipras, conceded a "serious political defeat" and said he would leave his future in the hands of party members.
It was also a good night for several small far-right parties that won enough votes to enter parliament, including a party backed by a jailed former neo-Nazi activist.
Mr Mitsotakis said he believed Greece's democracy "mature enough to handle whatever temporary turbulence" might ensue. He is due to unveil his cabinet later on Monday.
