Ruling party candidate Tabare Vazquez has easily won Uruguay's presidential election, exit polls show, returning to power a left-leaning coalition that has legalised gay marriage and sought to create the world's first state-run marijuana marketplace.
Mr Vazquez, a medical doctor who was president from 2005 to 2010, beat centre-right candidate Luis Lacalle Pou, who had said he would shut down much of the groundbreaking pot plan which has drawn international attention.
Mr Vazquez has promised to leave in place the plan to have the government regulate the cultivation and sale of marijuana on a nationwide scale, unless it produces negative results. His win is seen as a victory for the scheme.
Three exit polls broadcast on the South American country's main television stations all showed Mr Vazquez beating Mr Lacalle Pou by a roughly 10-point margin.
Two polls showed Mr Vazquez with 54% of the votes compared to 41% for Mr Lacalle Pou, and the third had the margin at 52% to 42%. Official results have not yet been released.
In October, Mr Vazquez fell just short of an outright victory in the first round of voting, getting 48% support against 31% for Mr Lacalle Pou.
He replaces president Jose Mujica, who was barred by law from running in Sunday's election. Both men belong to the ruling Broad Front coalition, and the Vazquez win is seen as heralding a continuation of government policy.
Mr Vazquez shook up Uruguayan politics when he became president in 2005, peacefully ending 170 years of two-party dominance in this nation of 3.2 million people.
Tall and trim, the 74-year-old oncologist is almost the physical opposite of Mr Mujica, who is short, paunchy and famously informal. But both support social programmes which have focused on the poor as well as continuing moderate economic policies.
In his first presidential campaign, Mr Vazquez promised changes that would "shake the roots of the trees". But he governed as a relatively cautious moderate, avoiding the constitutional changes and polarisation that have shaken countries such as Venezuela.
Mr Lacalle Pou, 41, is the son of another ex-president, Luis Alberto Lacalle Herrera, who governed from 1990 to 1995. A 41-year-old lawyer, he has promised to improve education and public security, areas in which Mr Mujica's government was often criticised. He has also said he would shut down the state-run marijuana market, while allowing domestic cultivation of the plant.
He is hobbled by some voters' wariness of a return to the traditional parties that ruled through most of the country's usually peaceful history, apart from a 1973-85 military dictatorship.
Son of an oil worker, Mr Vazquez grew up in a working class neighbourhood of Montevideo and went on to achieve a medical degree.
He continued seeing patients one day a week during his previous presidency, but said in a recent interview that he would give up medicine to focus on the presidency if elected.
Mr Lacalle Pou later conceded defeat, adding: "I wish him great success."