Rev Raphael Warnock - pastor for 15 years of a church that was at the spiritual heart of the civil rights movement - looks set to make history as the first black senator of the former confederate state of Georgia.
He also becomes only the 11th black senator in US history.
In a speech streamed online as he moved ahead of his Republican rival, he said his "roots are planted deeply in Georgia's soil"; one of seven southern states that fought for slavery during the US Civil War.
He talked of his "improbable journey" that began with his upbringing in public housing in Savannah, as the 11th of 12 children born to Jonathan, also a pastor, and Verene. His mother, he said, worked as a cotton-picker when she was younger.
"The other day, because this is America, the 82-year-old hands that used to pick somebody else's cotton went to the polls and picked her youngest son to be a United States senator," he said.
A graduate of the historically black Morehouse College in Atlanta, Rev Warnock worked as a youth pastor in New York City in the 1990s before moving to Baltimore, one of the poorest cities in the US.
There, he worked to educate his congregation about the risks of HIV/Aids, which was running at crisis levels among African-Americans. He also supports access to abortion, making him a rarity among faith leaders, and opposes the death penalty.
In 2005, he took up the post at Ebenezer Baptist Church in Atlanta, Georgia - the church where Dr Martin Luther King was baptised and once preached. Rev Warnock became the youngest senior pastor in the history of the church, which has become synonymous with the history of African-Americans' fight for civil rights.
Rev Warnock has clashed with authority. He was arrested in 2014 for taking part in a protest against the refusal of Republicans to expand Medicaid healthcare coverage. Three years later, he was arrested again, this time as one of several pastors protesting against moves to repeal the Affordable Care Act, which makes it easier for Americans to get health insurance.
Fair pay and voting rights are other causes he has fought for.
One member of his congregation, Cecilia Baker, told NBC that Rev Warnock has a "commitment to fairness that is unwavering".
"His messages on Sunday are uplifting and almost always educational about the political landscape and how it impacts black people. He fights for his community from the pulpit and will do the same in Washington," she said.
On the campaign trail, President Barack Obama said of the man who gave the benediction at his second inauguration in 2013: "You don't find a lot of people in Washington like Rev Warnock. And that's exactly why we've got to get him in office."
Rev Warnock has said his principles are driven by his faith. "I've always tried to leverage the moral truth to create moral good. My whole life has been about service. And that doesn't end at the church door, it starts there."
In his message to Georgians following his projected win, he said: "I am honoured by the faith that you have shown in me. And I promise you this tonight: I am going to the Senate to work for all of Georgia."