Lai, from the governing Democratic Progressive Party (DPP), took 40.2 percent of votes cast on Saturday, according to partial results from the Central Election Commission after 98 percent of polling stations closed.
Lai promised to stand “on the side of democracy” and defend the self-ruled island from “intimidation” from China, which claims Taiwan as part of its territory.
Lai, the current vice president, was in a three-way race with Hou Yu-ih from the conservative Kuomintang (KMT) and former Taipei Mayor Ko Wen-je from the Taiwan People’s Party (TPP).
The DPP favours a higher international profile for Taiwan as a de facto independent state, while the KMT promised closer ties with China but potentially better economic relations, and the TPP, which was founded in 2019, offered an untested but new third way between the other parties.
Taiwan’s elections carry an outsized importance because of the territory’s disputed political status. While self-governed since the 1940s, China still claims the island and its outlying territories and has not ruled out the use of force to achieve its ambitions.
In the run-up to the polls, China denounced Lai as a dangerous separatist, said he would be a threat to peace in the region if he won, and called the elections a choice between “peace and war“.
Voters also elected politicians to Taiwan’s 113-seat legislature on Saturday.
The DPP has been in power for the past eight years under President Tsai Ing-wen.
Some 19.5 million people aged 20 and over were eligible to vote.