Thai voters in Malaysia packed the early polling venue at the Thai embassy in Kuala Lumpur, prompting staff to pledge to stay open until the last person had cast their ballot.
Long queues had built up outside the embassy, the only overseas voting station in Malaysia, which led to the staff keeping the unit open past its allotted closing time.
According to Election Commission (EC) president Ittiporn Boonpracong, the polling station will also be open today.
"The embassy has offered an apology to everyone through the EC for any inconvenience caused," he said.
The Kuala Lumpur polling station had prepared three voting booths, which were capable of handling 180 voters per hour.
However, 4,139 people, many of them first-time voters, had registered to vote in Kuala Lumpur. Mr Ittiporn said the EC has asked the Thai embassy in Malaysia to add six more voting booths.
A large crowd of voters gathered outside the Thai embassy in Kuala Lumpur hours before the polling station opened at 8am.
Some of them are said to have fainted while waiting anxiously in a long line for their turn to vote.
Yesterday's vote was expected to close for the day at 9pm and will resume at 8am today until the last voter has cast their ballot, the Thai embassy in Kuala Lumpur wrote on its Facebook page yesterday.
Meanwhile, the two-day overseas vote in neighbouring Singapore ran smoothly yesterday, said Mr Ittiporn who was in the island state to inspect the process.
The overseas vote is being conducted from March 4-16 through three channels -- at a designated polling station, via mail or by mobile polling units, said EC secretary-general Jarungvith Phumma.
A total of 2.7 million voters have registered for advance voting both in Thailand and overseas. Of them 119,184 people are based overseas.
In the last general election in 2011, 2.6 million voters registered to vote early, said Mr Jarungvith, citing figures from the Interior Ministry.
Also, 16,183 Thais have shown their intention to join the vote in Australia, the highest number of registered overseas voters.
In Sydney, the vote is being carried out last week and this week from Monday to Friday at the Thai consulate.
A special round of voting was organised at a hotel in Sydney's Thai town for the voters unable to go to the polls on weekdays.
