"We didn't win in this round. We will make Likud's life hell in the opposition," Yair Lapid, number two in the centrist party led by former military chief Benny Gantz, said in a televised statement, referring to Netanyahu's right-wing party.
Earlier on Wednesday, Netanyahu said that he had already started coalition talks with right-wing parties, despite the fact that the official results of Tuesday's parliamentary elections have not yet been announced.
Following the announcement, US President Donald Trump hastened to congratulate Netanyahu with the victory.
According to preliminary results published by Israel's Central Elections Committee, 11, or possibly 12, of the whopping 40 parties which participated in the vote will enter the Knesset.