Benjamin Netanyahu is poised for a fifth term as Israel's prime minister, but intense political battles may lie ahead.
The incumbent's main rival, Benny Gantz, has conceded defeat after Tuesday's election - but has vowed to make "life hell" in opposition.
With more than 99% of votes counted, Mr Netanyahu's Likud Party looks like it will be able to muster enough support to control 65 of the Knesset's 120 seats - and be named as the head of the next coalition government.
Yair Lapid, a senior official in the rival Blue and White Party, said: "We didn't win in this round. We will make Likud's life hell in the opposition."
He also vowed to "show the people of Israel what a real alternative looks like".
Mr Netanyahu's campaign focused on his strong relationship with US President Donald Trump and his success in fostering ties with new allies such as China, India and Brazil.
Mr Trump phoned Mr Netanyahu to offer his congratulations from Air Force One, with the newly elected prime minister saying that he thanked his American ally for his "tremendous support for Israel".
Speaking to reporters, Mr Trump said the re-election improves the chances of peace between Israel and the Palestinians, adding: "He's been a great ally and he's a friend. I'd like to congratulate him on a well-thought-out race."
The election victory is set to give Mr Netanyahu a boost as he braces for the likelihood of criminal charges in a series of corruption scandals.
Israel potentially now faces weeks of political negotiations over the composition of a ruling coalition.
President Reuven Rivlin will consult with party representatives next week before picking the candidate with the best chance of assembling a parliamentary majority.
For the first time, these discussions are going to be broadcast live on television "in the name of transparency".
Netanyahu's future
This would be Mr Netanyahu's fourth consecutive term and his fifth overall - and this summer, the 69-year-old could become the country's longest-serving leader.
The race has been rocked by bribery and fraud allegations against Mr Netanyahu - who could become the first Israeli prime minister to face indictment while in office.
Over the weekend, he claimed he would annex Jewish settlements in the occupied West Bank if re-elected.
There are around 2.5 million Palestinians living in the West Bank, and it is seen by Palestinians as the heartland of any future state.
There are also around 400,000 Israeli settlers living in the area.
The settlements are considered illegal under international law - a view rejected by Israel.
There has been no official reaction to the election result from the Irish Govenment, but on Monday Tánaiste Simon Coveney criticised reports of further decisions on settlement construction in the West Bank.
He said: "I condemn the latest reported decisions by the Israeli authorities to advance plans and tenders for further settlement construction in the West Bank.
"The great majority of these plans and permissions relate to areas deep within the West Bank.
"Continued expansion of settlements in these areas is not compatible with a good faith effort to reach a peace agreement, and adds to the concerns raised by election promises in recent days to annex lands in the West Bank."
Main image: Benjamin Netanyahu shakes hands with a member of the Likud Party at a post-election event | Image: Oliver Weiken/dpa