Sen. Lindsey Graham, R-S.C., moved closer to serving a fourth Senate term, emerging victorious from the Republican field after South Carolina’s primary election Tuesday.

Graham defeated Duke Buckner, Michael Lapierre and Joe Reynold in the GOP primary race and will now face off against Democrat Jaime Harrison, who was unopposed in his party’s primary.

SEN. GRAHAM REFUSES TO LET FISA ABUSE GET PINNED ON LOW-LEVEL FBI STAFF: 'I BELIEVE IT GOES TO THE VERY TOP'

“To the voters, we’re going to have a real contest in the fall,” Graham said in a video statement posted Tuesday night. “How do you stay safe and prosperous? That’s the big issue. There’s going to be a real difference in opinion about how to do that. I really do believe prosperity is best achieved when people have more money to spend, not less.”

Soon after Graham officially won his contest, Harrison issued a letter challenging him to a series of debates ahead of November’s general election.

“All South Carolinians deserve the opportunity to hear from their candidates for U.S. Senate,” the letter said, according to The Associated Press.

SANDERS, AOC BACK KENTUCKY PROGRESSIVE, LOOK TO SPOIL CENTRIST DEM'S GAINS AGAINST MCCONNELL

President Trump has supported Graham in his reelection bid, campaigning with him in February. Vice President Pence also helped launch Graham’s campaign last year.

Harrison, an associate chairman with the Democratic National Committee and former chairman of the South Carolina Democratic Party, aimed to draw national attention since his campaign began, helping him spark the kind of significant fundraising and grassroots organizing that would be crucial to flipping a key Senate seat in a deeply red state.

CLICK HERE FOR THE FOX NEWS APP

Both Graham and Harrison have posted record-setting fundraising hauls in recent quarters. Over the course of the campaign, Harrison has raised nearly $15 million. Graham has taken in a total of $21 million, according to Federal Election Commission records.

The Associated Press contributed to this report.