Murders, gun smuggling, fuel theft, extortion and other crimes carried out by local criminal groups allied with Mexican cartels and the Albanian mafia have spiked in the past five years as the economy has struggled to recover post-COVID-19 pandemic and unemployment has risen.
Noboa, who has been president for 16 months after beating Gonzalez in a 2023 race to finish out his predecessor's term, finished just 16,746 votes ahead of his rival in a February first round and pollsters say either could win.
Both candidates and Gonzalez's mentor, former president Rafael Correa, have urged their observers to guard against potential fraud.
They each have more than 45,000 polling place observers.
Noboa, a 37-year-old business heir, says his "Phoenix" security plan, including military deployments on the streets, beefed up port security and more seizures of drugs and guns, is paying dividends, including a 15 per cent reduction in violent deaths in 2024.
"Ecuadoreans want real change," Noboa said at his final campaign event in Guayaquil on Thursday.
"This Sunday we will teach a lesson to that failed revolution, to those bad officials who attack us, to all the mafias that have taken our peace and to all the corruption that has stopped us moving ahead."
Noboa has predicted four per cent economic growth this year if his policies - including an increase in tax take and some austerity measures - continue.
He has pledged to prevent new energy cuts and boost the oil sector with private investment.
He has also taken recent measures - like distributing payouts to people affected by an oil spill and small businesses hit by flooding - which seem geared toward winning votes.
Gonzalez, who has promised to revive social programs enacted by Correa during his decade in power beginning in 2007, as well as improve security, says Noboa has improvised his governance.
"Has your life gotten better in these 15 months? Or worse? You have the answer: in your wallet, in your house, in your heart," she said in a Thursday social media video.
"This Sunday we choose between continuing to fall and getting up together to defend hope."
Gonzalez has pointed to a year-on-year uptick in killings in January and February as evidence Ecuadorians remain unsafe and said she would deploy 20,000 new police if she won.
She has secured the support of a significant part of the country's Indigenous movement, though Indigenous groups in the Amazon say they will back Noboa.
Gonzalez, who said during her 2023 campaign she could use international reserves for social programs, would need to manage delicate relationships with the International Monetary Fund, foreign investors and the administration of US President Donald Trump if elected.
Gonzalez would be the first woman elected president of Ecuador if she wins.
She has said she, and not Correa, will govern, but some lawmakers from their Citizens' Revolution party have suggested the former president - who was sentenced to eight years in prison on corruption charges in 2020 and currently resides in Belgium - could return to Ecuador.
