The 21-year-old's win came one day after the South American country won their first medal of any colour when Robeilys Peinado took the bronze in the women's pole vault.
"What great pride to see the victory of our Yulimar Rojas, a glorious athlete of the golden generation," tweeted Venezuela President Nicolas Maduro, whose country is embroiled in an economic and constitutional crisis.
Colombian Ibarguen, who has dominated the event over the last few years and won gold in Rio de Janeiro last year ahead of Rojas, was denied a third successive world title.
Ibarguen was leading with 14.89 metres until the fifth round when Rojas produced a leap of 14.91, the fourth time the lead had changed hands.
Rojas, who is coached by retired Cuban long jump Olympic champion of 2000 Ivan Pedroso and trains in Spain, celebrated her win effusively, jumping up and down and flapping her arms before going off to hug members of her family.
"It was a really tough battle but I'm an athlete who never gives up," said Rojas. "This is a great victory for my country. I am sure they will be celebrating and having a party. Thanks for everything, to my friends, family, my coach and Venezuela."
However, she added she was saddened by the situation in her home country where some 120 people have been killed during four months of sustained anti-government protests and Maduro has faced global pressure to dismantle a newly created pro-government constituent assembly which has been condemned as a power grab.
"I'm sad about what is happened in my country, which is a wonderful country... I know that one day we will put a stop to this all this, all this fighting and this war between brothers,"
Rojas said. "I hope I've made my country proud."
Venezuela's socialist government invested heavily in sport under late President Hugo Chavez but many athletes complain that state funding has dried up under the country's brutal economic crisis.
Ibarguen, 33, had dominated the sport since taking Olympic silver at the London Stadium in 2012, at one point enjoying a 34-meeting winning streak that lasted until early June 2016.
But Rojas has made her life much tougher since bursting onto the scene. "I will keep working hard. I am satisfied with my performance," Ibarguen said.
(Writing by Brian Homewood; Editing by Ken Ferris and Christian Radnedge)
