Gustavo Petro was elected the first ever left-wing president of Colombia on Sunday, after beating millionaire businessman Rodolfo Hernandez in a tense and unpredictable runoff election.

With all votes counted, Petro - the 62-year-old former mayor of Bogota - won with 50.4% compared to Hernandez's 47.3%.

"As of today, Colombia is changing, a real change that guides us to one of our aims: the politics of love ... of understanding and dialogue," Petro said.

Hoy es dia de fiesta para el pueblo. Que festeje la primera victoria popular. Que tantos sufrimientos se amortiguen en la alegria que hoy inunda el corazon de la Patria.

Esta victoria para Dios y para el Pueblo y su historia. Hoy es el dia de las calles y las plazas.

— Gustavo Petro (@petrogustavo) June 19, 2022

Hernandez, 77, accepted the result, in which he came up short by 700,000 votes, in a Facebook live broadcast.

"I hope that Mr. Gustavo Petro knows how to run the country and is faithful to his discourse against corruption," he said.

Speaking to supporters at his party headquarters in Bogota, Petro stressed that "this is not a change to deepen sectarianism in Colombia. The change consists precisely of leaving hatred behind, leaving sectarianism behind."

"We want a Colombia that through its diversity is one Colombia," he added.

Colombia's first black woman vice president

In the same context, Francia Marquez, 40, will become Colombia's first black woman Vice President.

"The great challenge that all of us Colombians have is reconciliation," said Marquez, adding that "the time has come to build peace, a peace that implies social justice."

Leftist leaders congratulate Petro

Leftist leaders in the Latin American region were quick to congratulate Petro.

"Gustavo Petro's victory is historic. Colombia's conservatives have always been tenacious and tough," tweeted Mexico's President Andres Manuel Lopez Obrador.

El triunfo de Gustavo Petro es histórico.

Los conservadores de Colombia siempre han sido tenaces y duros. El escritor José María Vargas Vila relataba que los dictadores de su país "mojaban en agua bendita su puñal antes de matar". 1/3

— Andrés Manuel (@lopezobrador_) June 19, 2022

Chile's President Gabriel Boric said, "Joy for Latin America! We will work together for the unity of our continent in the challenges of a world-changing rapidly."

Similarly, Venezuela's President Nicolas Maduro considered that "the will of the Colombian people has been heard, it went out to defend the path to democracy and peace."

Felicito a Gustavo Petro y a Francia Márquez, por la histórica victoria en las elecciones Presidenciales en Colombia. Se escuchó la voluntad del pueblo colombiano, que salió a defender el camino de la democracia y la Paz. Nuevos tiempos se avizoran para este hermano país. pic.twitter.com/FxodCn9Uqx

— Nicolás Maduro (@NicolasMaduro) June 19, 2022

Meanwhile, US Secretary of State Antony Blinken congratulated "the people of Colombia for making their voices heard in a free and fair presidential election."

Tough challenge for the new President

The electoral observer mission said one of Petro's election monitors and a soldier were killed, both in the south.

Petro will have to deal with a country reeling economically from the coronavirus pandemic, a spike in drug-trafficking-related violence, and deep-rooted anger at the political establishment that spilled over into mass anti-government protests in April 2021.

Almost 40% of the country lives in poverty, while 11% are unemployed.

It is noteworthy that the new Colombian President was born on April 19, 1960, and is a well-known politician, economist, and activist who, in his youth, joined the April 19 Movement - a militant faction that participated in the internal armed conflict between 1974-1990.