Benin's President Patrice Talon promised a "KO" first-round victory in Sunday's election on his last campaign rally in Cotonou before the vote, which has been mired by violence.
Election buildup has been marked by protests in opposition strongholds. On Friday, a second person died a day after troops opened fire to break up a protest in the city of Save.
A government spokesman Alain Orounla said on Thursday security forces were attacked by "drugged and armed" youths and had responded when they came under fire.
Critics say Talon has steered the country into authoritarianism but his team says otherwise,
"To say that President Patrice Talon's record is catastrophic is a utopia, and it's not true," said Gregory Adounvo, leader of the Republican Bloc.
"When we take stock, look back at what was before, and what is today, it is normal that the reforms can bother people because when we talk about reforms, it is already to be able to impose on people ways that they did not use before."
**Vote 'already rigged' **
Talon, a cotton magnate first elected in 2016, faces off against two little-known rivals,
He is expected to easily win a second term, with most of his main opponents exiled or sidelined.
One opposition leader Reckya Madougou was detained last month on accusations of plotting to disrupt the election with terrorism, a charge her lawyer says is fabricated.
His opponents say the vote is already rigged.
A judge from the special court created by Talon also fled the country this week after denouncing political pressure to make rulings against opponents, including the decision to detain Madougou.
The US, German, French and Dutch embassies as well as the EU delegation in Benin all called on Friday for calm and for the vote to go ahead in a free and transparent manner.
"We urge all parties to express their perspectives peacefully," US State Department spokesman Ned Price told reporters.
"We urge the electoral institutions and courts overseeing these processes and verifying these results to ensure these elections are conducted freely, fairly, and transparently."
Results are expected to be announced on Monday or Tuesday.