MANILA, Philippines - Benigno Aquino was on course Monday for a landslide win in the Philippine presidential race after an historic election that saw millions of Filipinos embrace his promise to fight endemic graft.

The senator's emphatic early lead in the vote count came after a tumultuous polling day in which 10 people were killed across the country, and technical glitches marred the introduction of an automated polling system.

Aquino, son of the Southeast Asian nation's most revered democracy heroes, established a huge lead over former president Joseph Estrada with 38.25% of the vote counted on Monday night, the election commission said.

Aquino had secured 40.44% of the votes counted, with Estrada on 25.76% and business titan Manny Villar in third place with 13.98%, Commission on Election chair Jose Melo told reporters.

Estrada enjoyed the most emphatic win in Philippine electoral history in 1998 when he received 39% of the vote.

Although the commission needed to count more votes before declaring a winner, the early trends reflected opinion polls carried out ahead of Monday's election that showed Aquino would swamp his rivals.

Aquino deftly tapped into popular sentiment for his parents by pledging a new style of clean government following nearly 10 years of rule under President Gloria Arroyo, whose reign has been tainted by allegations of massive graft.

"Corruption is the single biggest threat to our democracy," Aquino, a 50-year-old bachelor who has an economics degree, said on his official blog.

His mother, former president Corazon Aquino, led the "people power" revolution that overthrew dictator Ferdinand Marcos in 1986.

His father, Benigno "Ninoy" Aquino, was shot dead three years earlier as he attempted to return from US exile to lead the democracy movement against Marcos.

The bespectacled Aquino was a latecomer to the presidential race, declaring his candidacy only after his mother's death from cancer last August plunged the country into mourning and demonstrated the power of the family name.

About 75% of the 50 million eligible voters turned up at polling stations on Monday, reflecting Filipinos' deep commitment to democracy.

But violence that always plagues Philippine politics inevitably flared.

More than 17,000 positions were at stake -- from president down to municipal council seats -- and local politicians who are infamous for using their "private armies" to eliminate rivals or intimidate voters were out in force.

Ten people were killed on polling day, bringing the death toll from election-related violence over the past four months to at least 40, according to police statistics.

Two of the fatalities occurred as gunbattles raged in the flashpoint southern province of Maguindanao, where 57 people were killed in an election-linked massacre late last year.

Technological problems also emerged immediately after polls opened with some machines breaking down, and the election commission was forced to extend the voting period by one hour as long queues formed.

Nevertheless, the election commission and security chiefs insisted the country's first effort at automated polling had succeeded.

The elections "will go down in our nation's history as probably the most peaceful and orderly political exercise ever held in our land," national police director general Jesus Verzosa said.

Many colourful characters contested the elections, including world boxing champion Manny Pacquiao, 31, who ran for a seat in the lower house.

Another candidate for the lower house was Imelda Marcos, 80, who gained global notoriety when thousands of her shoes were found in the presidential palace after her late husband overthrow in 1986.