Harriette Thompson, 92, became the oldest woman to complete a marathon on Sunday when she finished the San Diego Rock n’ Roll Marathon in 7:24:36. She surpassed the record set by Gladys Burrill, who ran 9:53:16 at the 2010 Honolulu Marathon, 19 days after her 92nd birthday, when she was 74 days younger than Thompson is now.

Thompson told Runner’s World Newswire Thursday night, “I’ll be the most surprised person if I finish it. I hope I will!”

The cancer survivor, concert pianist, and grandmother of 10 covered the course in 16:59 per mile, with a combination of running and walking. Thompson, of Charlotte, North Carolina, has run the San Diego race for the Leukemia and Lymphoma Society 16 times since 1999, missing only the 2013 race as she battled cancer.

Upon finishing yesterday’s race, Thompson told competitor.com, “I thought it was like Lindbergh coming in after his flight,” of the response that greeted her at the finish line.

“I was really tired at one point. Around Mile 21, I was going up a hill and it was like a mountain,” she told the Charlotte Observer after the race, “and I was thinking, ‘This is sort of crazy at my age.’ But then I felt better coming down the hill.”

Thompson has had a challenging year as she lost her husband of 67 years, Sydnor Thompson, to cancer in January and dealt with painful wounds on her legs, a result of radiation treatment she underwent to treat squamous cell carcinoma. Many of Thompson’s family members and friends have battled cancer.

“That makes it personal, something that I really feel is important,” Thompson said of her running for a cause. She has raised more than $100,000 for the Leukemia and Lymphoma Society in 16 years of running the race.

As far as she knows, Thompson is cancer-free right now, however, and heading into Sunday’s race, she even entertained thoughts of trying for the 7:07:42 90–94 age group world record she established a year ago.

Her son, Brenny Thompson, 56, has accompanied his mother during the race in recent years. He helps make sure that she has the fuel she needs, serves as a bodyguard, and fields photo requests along the way.

“Since I’m so old, everybody wants to have their picture taken with me. Brenny says, ‘Don’t stop her, just take a selfie,’ rather than stop and take pictures all the time, because I’d never get to the end. But it’s funny, all you need to do is get to be 90-something and you get lots of attention,” Thompson said.

Thompson says that as long as she is able to, she will continue running the San Diego race.

“I keep thinking, ‘I don’t deserve this [attention],’ but if it helps or if it encourages anybody, it makes me feel good,” Thompson said. “I think if I can do it, anybody can do it, because I wasn’t trained to be a runner. But I have also found that it’s very invigorating. I feel like a million dollars when I’m finished.”