In 72 hours, freshman Justin Diamond turned the race for Student Association president on its head.

Diamond launched an 11th-hour campaign for the SA’s top spot Monday night, two days before students could begin voting, and quickly garnered the support of more than 1,300 students. His candidacy split the vote share nearly equally among four candidates, likely forcing the SA’s first runoff election in seven years.

“With the excitement around the election, especially with the presidential election over the past few days, I had a feeling that it was a real possibility,” James Ingram, the chairman of the Joint Elections Commission, the body that oversees SA elections, said.

Diamond, who is running on a campaign of eradicating the SA, will face off against junior SJ Matthews, the president of the Residence Hall Association, over a 12-hour voting period Thursday. While candidates said the runoff was unexpected, they hope the extra week will give them an opportunity to galvanize students to vote again in an election that could define the future of GW’s student government.

Diamond and Matthews captured 27 and 25 percent of the vote last week, respectively, but candidates need at least 40 percent of the vote to win the presidency, according to the SA constitution. Two other candidates for president were eliminated from the runoff election after the initial round of voting last week.

While a runoff election hasn’t occurred since 2012, they were commonplace in the years before. The JEC held a runoff election for SA president in 2012 and a race for both president and executive vice president in 2011. Elections also led to a runoff twice in 2009 and 2008 for the presidency.

Ingram, the chairman of the JEC, said that in a runoff election, candidates are allowed to spend an additional $100 on their campaigns and can seek endorsements from those already elected to the SA Senate. While Diamond did not register with the JEC to run for president, his name will appear on the ballot, and voters will have no option to cast a write-in vote, he said.

Matthews, who has highlighted community building in her platform, said the runoff election is “stressful” because she thought she would finish campaigning last week. She will hold listening sessions in Kogan Plaza, District House, the Marvin Center and on the Mount Vernon Campus this week to talk with students ahead of the election, she said.

“I think for me, personally, it’s great to see that the student body supports me and that they consider me a good candidate to have made it to the runoff,” Matthews said.

Matthews ran on a platform of giving all students tap access to residence halls and expanding the number of lounge areas in the Marvin Center.

She added that she has reached out to SA senator-elects to congratulate them on their races and has planned meetings with student theater organizations in the hopes of securing additional endorsements.

“I’m going to continue talking to them about the issues that matter on this campus, about what I can do to fix them and how we can actually build a good GW,” she said.

Diamond said his campaign has built a sense of community on campus, and moving to a runoff election shows that a large share of students believe that the SA is unproductive. If elected, Diamond would be the first freshman and write-in candidate to be elected SA president in recent memory.

“I have a lot of students behind me and I’m excited to keep rallying support for our cause,” he said. “I was just very proud of my friends and all of the people who came out to help.”

Heading into the week, Diamond said he will not spend any money on his campaign because “it doesn’t require money to be the voice of students.” Diamond has also pledged to renounce the SA president’s $15,000 scholarship if elected.

He said he will spend the next few days meeting with students to ensure voters understand that his candidacy is not part of a “joke campaign” but includes a viable plan to cut or significantly reform the SA. Diamond released a formal platform Sunday called the “Diamond Standard,” which details his top two priorities in-depth.

“We may joke and we may have fun, but this campaign is very serious,” Diamond said. “There’s a real platform behind it, and I think that it’s very telling when the opposition writes off our entire platform as a joke and says that people voting against them are simply kidding around.”

Zach Schonfeld contributed reporting.