Columbia University's newest graduate is 52-year-old custodian Gac Filipaj who collected his diploma from the Ivy League school with honors after working on his degree for 12 years.

"I proved that I have enough strength to finish what I started to do," Filipaj told ABC News at Sunday's ceremony.

The Yugoslavian-born custodian donned Columbia's baby blue cap and gown for the ceremony. He smiled from ear-to-ear as the crowd erupted into cheers as he crossed the stage to accept his diploma. After the ceremony, a group of students chanted his name as he posed for pictures.

(Image credit: Jason DeCrow/AP Photo)

Filipaj graduated with a bachelor's degree in classics with honors from Columbia's School of General Studies. He called it the "best moment in my life so far."

Filipaj fled to the United States from war-torn Yugoslavia in 1992, leaving behind his parents and siblings on a family farm in Montenegro. He arrived in New York speaking virtually no English and settled in the Bronx where he started taking English classes at Theodore Roosevelt High School.

He took a job as a custodian at Columbia for six years while he learned to speak English. When he was proficient enough, he began taking classes part-time, using the school's tuition exemption for employees.

The dedicated student and worker would go to class in the morning and then do his custodian work from afternoon until night before heading home to the Bronx to study.

One or two classes a semester and 12 years later, his hard work has paid off.

(Image credit: Jason DeCrow/AP Photo)

"He was tenacious about keeping to his schedule and really fulfilling his goal," Filipaj's boss Donald Schlosser, assistant vice president of facilities for the university, told ABC News.

Filipaj wants to take a semester off to focus on his job and then he plans to start studying again, probably at Columbia where he would get the tuition exemption.

"I would like to go to graduate school, either for a masters or, even better, for a PhD," he said with a broad smile.