The 33-year-old media executive and investigative journalist managed to beat the pundit's predictions – and his own – and secure more than 50% of the vote in a race with seven candidates, avoiding a runoff election later this summer between the top two vote-getters.
"This is not a moment to let up. This is a moment to double down – because the task before us is a mighty one," Ossoff said in a brief victory speech Wednesday night.
He said that President Donald Trump and his Republican allies on Capitol Hill are "leading this country down a dark path" – one of authoritarianism, racism and corruption – and that the country "can't go down it any longer."
With such a large field of candidates, the race was expected to advance to a runoff on Aug. 11, especially since two of those candidates – former Columbus, Georgia, Mayor Teresa Tomlinson and 2018 lieutenant governor candidate Sarah Riggs Amico – ran well-financed campaigns. Ahead of Tuesday's election, Ossoff said in an interview that it would be "an unprecedented, historic, herculean achievement" to avoid a runoff election under the circumstances, and said his campaign was "fully prepared to win a runoff."
But in his Wednesday night remarks, Ossoff looked to the general election and made a call out to all Georgians.
"Whether you identify as a Democrat and have your whole life, whether you're an independent or Republican or apathetic, now is the time to stand up and make a change in this country. Now is the time to stand up and make a change in this state," Ossoff said.
With both Senate seats on the ballot this November, Democrats are eyeing Georgia as a potential pick-up opportunity as they aim to flip control of Congress's upper chamber. After Gov. Brian Kemp's mere 1.4-point victory over Democrat Stacey Abrams in the 2018 gubernatorial election, it's seen as a new battleground state this cycle.
Democratic Party of Georgia Chairwoman Nikema Williams said Ossoff "is a fighter against Washington corruption and a champion for hardworking Georgia families," and predicted he'd turn Georgia blue this November, saying he'll be "an excellent U.S. Senator."
She added that the "party is stronger" because of the many candidates who ran, saying, "Now, Georgia Democrats are ready to unite and take on Republicans up and down the ballot this November."
"Senator David Perdue said it best: Georgia is in play," said Senate Majority PAC President J.B. Poersch. "While in Washington, Sen. Perdue has become the quintessential D.C. politician. While Georgia was battling COVID-19, Sen. Perdue was caught trying to get rich off of a global health crisis... Jon Ossoff has made it his mission to stand up to the corruption in Washington, making him the perfect foil for Sen. David Perdue, who has been looking out for his own interests over the needs of working families."
Nathan Brand, spokesperson for the NRSC – Senate Republicans' campaign arm – said Ossoff "may be one of the most unprepared and unaccomplished individuals ever to seek this office."
"His reliance on an embellished resume, insider liberal connections, and campaign cash from far-left New York and Hollywood donors is why Georgia voters can't trust Ossoff to represent their values. This race will end like Ossoff’s other political adventures – in embarrassing defeat," Brand said.
Ossoff told ABC News Monday that Republicans would go after him for his age and lack of political experience.
"I don't have the typical political profile," he said. "First of all, I'm young, and David Perdue and his allies will try to turn that against me, but I believe it's one of my greatest strengths."
Earlier Wednesday in a media availability, Ossoff repeatedly said it was "too early to talk about outcomes." Instead, he called for accountability at "all levels" for how Tuesday's primary election went, and put county and state officials "on notice" that his campaign would be making sure every vote was counted.
But before that press availability, the candidate who finished behind him – Teresa Tomlinson – had essentially declared a runoff election between herself and Ossoff, blasting him as an unelectable candidate because he couldn't secure a majority of the vote in any of the elections he's run.
“Now that most (votes) have been counted, it appears that for the third time in his political career, Jon Ossoff has failed to break the 50% needed to avoid a runoff,” Tomlinson said in a statement sent at 11:35 a.m. "Even though Jon is universally known, a majority of voters have rejected him again... I am confident voters will conclude that I am the candidate who can beat David Perdue in November."
It's clear now that Tomlinson spoke much too soon.
In a statement that came at 9:01 p.m. Wednesday, she thanked her supporters and competitors, and called for unity against Perdue.
"I want to thank my opponents in this race and congratulate Jon Ossoff on his victory," Tomlinson said. "I call on my supporters, and all Georgians, to do all they can to support Jon in his campaign to defeat David Perdue and Donald Trump in November."