President Jose Mujica will be succeeded either by his Broad Front ally Vazquez, who earned 44-46 per cent of votes yesterday, or the National Party's Lacalle Pou, who garnered 31-34 per cent, according to pollsters Equipos Mori, Factum and Cifra.
Some Vazquez supporters had hoped he could squeeze out an absolute majority, but it did not happen. Compounding their disappointment, his party was also seen as potentially losing its control over the legislature, the exit polls found.
The law, Mujica's landmark legislative initiative, was passed last December. But implementation is off to a rocky start, and it faces an uncertain future because Lacalle Pou opposes the law.
And even Vazquez, who made anti-smoking legislation the centerpiece of his own presidency, has questioned it and said he would not hesitate to make changes.
Surrounded by supporters, Mujica -- a former leftist guerrilla famous for living in a humble farmhouse while president and donating most of his salary to charity -- was one of the first to vote in the Cerro neighborhood west of the capital Montevideo.
Vazquez, 74, is out to reprise his 2004 election win, which ended 174 years of dominance by the South American country's two traditional parties, Pedro Bordaberry's Colorados (Reds) and Lacalle Pou's Blancos (Whites, now officially called the National Party).
"We are hoping for the best, but the people will have their say," he said on arriving to cast his ballot.
After 10 years in power, the Broad Front (FA) clearly has lost some of its shine with voters -- a feeling exit polls backed up.
