Evo Morales has coasted to victory in Bolivia’s presidential elections, winning an unprecedented third term as voters rewarded the former coca grower for delivering economic and political stability.

Morales, a native Aymara Indian, received 60% of the vote against 25% for cement magnate Samuel Doria Medina, the highest polling of four challengers in Sunday’s election, according to a quick count of voting stations by the polling firm Ipsos for ATB television. Official partial results were expected early on Monday.

Doria Medina conceded defeat late on Sunday, promising to “keep working to make a better country”.

Morales’s supporters poured into the streets to celebrate the triumph, but the festive mood was partly dented by an apparent failure by the ruling Movement Toward Socialism party to retain the two-thirds control of congress needed to push through a constitutional reform lifting a two-term limit on presidential mandates.

In a victory speech from the balcony of the presidential palace in La Paz, Morales dedicated his victory to Cuba’s Fidel Castro and the late Venezuelan president, Hugo Chávez.

“It is a triumph of the anti-colonialists and anti-imperialists,” Morales said in a booming voice. “We are going to keep growing and we are going to continue the process of economic liberation.”

Morales won eight of Bolivia’s nine states, including the former opposition stronghold of Santa Cruz, an agribusiness centre in the eastern lowlands where he polled 51%, according to Ipsos.

Morales is on track to become Bolivia’s longest-serving leader consecutively in office, eclipsing 19th-century Marshal Andrés de Santa Cruz, a founder of the republic in power from 1829-1839.

While known internationally for his anti-imperialist and socialist rhetoric, the 54-year-old coca growers’ union leader is widely popular at home for a pragmatic economic stewardship that spread Bolivia’s natural gas and mineral wealth among the masses.

A boom in commodities prices increased export revenues ninefold and under Morales’s watch Bolivia accumulated record international reserves and sold bonds abroad for the first time in nearly a century. Economic growth has averaged 5% annually, well above the regional average. Half a million people have put poverty behind them since Bolivia’s first indigenous president first took office in 2006.

Yet Morales has alienated environmentalists and many former indigenous allies by promoting mining and a planned jungle highway through an indigenous reserve. And despite Bolivia’s economic advancements, it is still South America’s poorest country. Nearly one in four Bolivians live on $2 a day, according to the World Bank.

Morales had sought on Sunday to improve on his previous best showing of 64% in 2009 and to maintain a two-thirds control of Bolivia’s senate and assembly needed to lift term limits.

He has not said whether he would seek a fourth term, only that he would “respect the constitution”.

A court ruled last year that Morales could run for a third term because his first preceded a constitutional rewrite. All seats were up for grabs in the 36-member senate and 130-member lower house. Results were not immediately available but exit polls indicate he fell just short of the needed threshold.