Another vote will take place on June 17 which could see the country’s already fragile peace deal with the FARC shaken.
Leftist Petro is a fan of the agreement which saw the country’s biggest rebel group put down their weapons to form a political party. Protege of popular ex-president Alvaro Uribe, Duque, wants to amend the deal.
The first round of presidential elections since the 2016 peace agreement saw over 19 million Colombians hit the ballot box – the highest turnout in 20 years.
A favourite from the start, Uribe’s right-hand man, Duque, expectedly got the highest number of votes, with over 7 million, or 39% of the votes.
Petro, who is promising social reform and to close the gap between the rich and the poor in the region’s most unequal nation, shocked commentators by picking up 25% of votes in a traditionally right-wing country.
Colombia’s first round of voting also saw centrist – and hugely popular – candidate Sergio Fajardo eliminated from the race with over 4.8 million votes (23.7%).
The mathematician did surprisingly well, trailing very closely behind Petro and beating all candidates in Bogota.
And former vice-president and the man who negotiated the 2016 peace deal with the FARC, Humberto de la Calle, left the race with just little over 2%.
This year’s elections are seen as particularly important as former rebel group the FARC – known for wreaking havoc on the country in the half-century civil war – were given the chance to form a political party following a peace deal which led them to give up their weapons.
Their party saw little success in the legislative elections in March though the hottest topic now is how to deal with FARC commanders who many believe should be locked up, rather than having a place in politics.
Many Colombians aren’t keen on the deal and the next president could potentially change the agreement.
The decider on June 17 will determine who is to deal with a country which, despite improving its security in the past decade, has faced troubles with armed groups filling a vacuum left by the FARC, unprecedented cocaine production and corruption.
Huge amounts of Venezuelan migrants flooding over the border to escape a worsening economic crisis and a struggling economy are also pressing problems for the next administration.