Tunisian polling firms have declared Beji Caid Essebsi, an 88-year-old official from previous regimes, as the winner of Sunday's presidential runoff, cementing his dominance over a country where his party already controls Parliament.

Sigma Conseil company's exit polls, which have consistently matched official results in Tunisia, gave Essebsi 55.5 percent of the vote and his opponent Moncef Marzouki, the outgoing interim president, 44.5 percent. Other polling companies gave similar figures.

However Marzouki's campaign maintained that Sunday's election was too close to call, and the official results are not expected for another 48 hours.

The runoff election, which saw low turnout by registered voters, marks the culmination of a 4-year-long rocky transition to democracy, with parliamentary elections in October and the first round of presidential elections a month later.

While the moderate Islamist party Ennahda dominated politics immediately after the revolution in 2011, they were unable to address the serious economic and political challenges in the country, including terrorist attacks.

Essebsi created Nida Tunis, a collection of former regime officials, businessmen and trade unionists to oppose the Islamists and to restore the "prestige of state," which he said had suffered in the wake of the revolution.

There are fears that Essebsi's domination over both the executive and legislative branches of the government could result in a return to the country's old authoritarian ways — an argument Marzouki attempted to push during his campaign.

In the end, however, Tunisians appear to have desired a return to stability and normalcy after the years of revolutionary turmoil.

"Essebsi, thanks to his political experience and international ties as well as his program, can get the country out of this mess," said Mehrez Rakkez, a lawyer who voted in the lower income neighborhood of Kram. He described Marzouki's three years as interim president as a disaster and said the vote was a choice between "life and death."

In nearly all the countries swept by pro-democracy uprisings since the Arab Spring, there has been a degree of backlash since the first heady days, including government crackdowns and Egypt's military overthrow of an elected president.

In Tunisia, however, the backlash has remained within the legal framework of the transition.

The Nida Tunis coalition declared victory almost immediately after the polls closed on Sunday and its celebrations had already begun at the party headquarters.

In contrast to the almost 70 percent turnout for the first round of the presidential election and the legislative balloting, the official election authority said only 56 percent of Tunisia's 5.3 million voters cast ballots on Sunday.

"This election doesn't interest me," said a young man sitting in a crowded cafe in front of a polling station in Tunis' lower income neighborhood of Yasmina. "I voted before, but I feel the candidates lie. They promise to create jobs for the youth and improve living conditions, but they don't keep them."

The eve of the election was marked by some violence with a shotgun blast wounding a soldier near the city of Kairouan. The attackers returned early Sunday morning and attempted to target another polling station but were caught by the army which killed one and arrested three.

No other major acts of violence were reported by the time polls closed at 6 p.m.

Islamic radicals had urged a boycott in a video that surfaced on social networks Wednesday.

According to authorities, around 100,000 police and soldiers secured the polls.