Prime Minister Mahathir Mohamad, Asia's longest serving leader, scored a decisive reelection victory Monday, securing more than a two-thirds majority in Parliament and extending by five years his 18-year run in power. But Malaysia's Islamic opposition party, known as Pas, made surprisingly strong gains in the Malay heartland, embarrassing Mahathir in his traditional ethnic stronghold.

Returns from Monday's elections showed that as of today, Mahathir's ruling National Front coalition had won 148 seats in the 193-seat Parliament, according to the election commission. The combined opposition parties ended up with 44 seats, double what they had in the just-dissolved Parliament.

The result suggests that for now, the region-wide reform movement that has swept away other authoritarian Asian systems has stalled in Malaysia, in the face of the ruling party's juggernaut. But Mahathir's large win obscures what many analysts say are fundamental, long-term changes underway here, as the population becomes younger, more connected to the world and less interested in Mahathir's old-style brand of paternalistic rule. Those changes may become more apparent in subsequent elections.

The ruling coalition won by piling up large margins in pro-government bastions such as Sawarak and Sabah states on Borneo island, and in Johor in the south. The National Front also did particularly well among ethnic Chinese voters, after a campaign that critics said played on Chinese fears of violence in the event of an opposition victory.

"Clearly, [the National Front] is the party of choice of the peoples of Malaysia," a beaming Mahathir, 73, told a cheering crowd of supporters, and journalists, in a hall at his party headquarters building downtown. "We will ensure that this country remains free, remains united and remains successful."

Despite the appearance that this was a status-quo election, Malaysia witnessed what amounts to a sea change in the politics of the Malay-dominated states of the north, the so-called Malay Belt. There, the Pan-Malaysian Islamic Party, or Pas, some of whose leaders have called for imposing strict Islamic law in Malaysia, seized control of the crucial heartland state of Trengganu, which is rich in natural resources. Pas also kept control of rural Kelantan state, the only one of Malaysia's 13 states not ruled by Mahathir's coalition.

It was in the Malay states of the north where sympathy ran deepest for Anwar Ibrahim, the popular former deputy prime minister who was fired, jailed and beaten in detention. Anwar is serving a six-year sentence for abuse of power and is currently on trial for sodomy. His plight has galvanized the once-squabbling forces of the opposition while deeply dividing Malays, many of whom appear to have defected to the Islamic camp.

Early results showed Pas sweeping as many as 29 of 32 state assembly seats in Trengganu. "We will be forming the government tomorrow," Secretary General Nasharudin Matisa said. He also said Kelantan, which Mahathir had pledged to retake, would be a "sweep" for the Islamic party.

Pas also was adding to its gains in the national Parliament by picking up new seats in Kedah, Mahathir's home state, and Perlis, another heavily Malay state.

The loss of Trengganu is a particular embarrassment for Mahathir because it represents the core of the Malay heartland and is a state with significant financial resources through its oil and gas fields. Most oil firms operating in Malaysia have facilities and investments in Trengganu. "If Pas gets their hands on Trengganu, it will give them a piggy bank," a Western diplomat said.

Another big winner for the opposition was Anwar's wife, ophthalmologist Wan Azizah Ismail, making her first run for public office for her jailed husband's seat. Azizah, leading the newly formed National Justice Party--which used the infamous black eye Anwar suffered in prison as its symbol--won handily.

"I am very happy, but I am sad," Azizah said in her new parliamentary district, in Penang state. "I wish my husband was around. And I am very grateful to the voters." About 300 Anwar supporters shouted "Reformasi!"--reform--after Azizah spoke at the local vote counting center.

Mahathir had disparaging words for Azizah after her victory, accusing her of riding in on a sympathy vote for Anwar, and for campaigning with one of her daughters who cried publicly over her father's fate. "Here come the wife and the daughter crying," Mahathir said. "So people sympathize. The question is whether she can now contribute anything at all."

The opposition gains were still not enough to deny Mahathir the two-thirds majority he had sought, and he tried to play down opposition gains. "We have unfortunately lost two states to the opposition," he said. "We'll get it back next time. But we accept that because ours is a democratic country."

CAPTION: Wan Azizah Ismail, left, leader of the opposition National Justice Party and wife of the imprisoned former deputy prime minister, speaks to a voter. In her first try for political office, she won her husband's parliamentary seat.