WATCH: Va. teen in wheelchair stuns classmates by walking at graduation

Of all the students in Hylton High School's class of 2015, Parker Haller was perhaps the most nervous on graduation day.

When the 18-year-old from Woodbridge, Virginia, accepted his diploma last week, it was the first time Parker's classmates had seen him walk since he suffered a spinal cord injury in a diving accident three years ago in Ocean City, Maryland.

At first, doctors said his chances of ever walking again were less than five percent. But after long and hard work at physical therapy, Parker has made amazing progress. About a year ago, Parker and his family set a goal.

"One way or another he is going to walk across that stage," mother Miriam recalled saying.

One of Parker's physical therapists wheeled him to the stage at graduation last Saturday. To the surprise of his classmates, Parker stood up and walked across the stage using a cane. The crowd at the Patriot Center erupted in cheers and applause.

"It was overwhelming and exciting at the same time," Parker said. "I was trying not to overthink it because I didn't want to fall down and ruin the whole moment. I was just focusing on walking across the stage."

Parker isn't done beating the odds. Next, he says he's working to walk without any type of assistive device.