Harriette Thompson, 92, and son Brenny Thompson, finish the Suja Rock 'n' Roll San Diego Marathon, May 31, 2015, Getty Images/Jerod Harris

Harriette Thompson, 92, became the oldest woman to finish a marathon Sunday, pounding the pavement for more than seven hours in San Diego. Perhaps more remarkably, she did so after surviving cancer three times and despite a recent staph infection in one of her legs.

"I was just really thrilled that I could finish today," she told the Associated Press after crossing the finish line at the Rock 'n' Roll Marathon. Thompson finished the race in 7 hours, 24 minutes and 36 seconds. She fell just short of her time last year -- 7 hours, 7 minutes and 42 seconds -- which set the record for a woman 90 or older.

Thompson, who is from Charlotte, North Carolina, has run in 17 of the last 18 Rock 'n' Roll marathons, each time on behalf of the Leukemia & Lymphoma Society. She said she only runs in the San Diego race because of its dedication to the cancer foundation, the Charlotte Observer reported. Thompson lost both her parents and three brothers to cancer. Sydnor Thompson, her husband of 67 years, died in January at the age of 90 after a long battle with cancer.

Harriette Thompson said this race was her most difficult. She set aside training to care for her sick husband, and after he died earlier this year, she underwent treatment on her infected leg, she told the AP. "It's always harder but this year has been a bad year for me," she said.

Thompson finished the marathon with her son Brenny, 56, also of Charlotte. During the race, she wore a purple T-shirt bearing the logo of Team In Training, a fundraising and sports training program for the Leukemia & Lymphoma Society. Her white tights concealed wounds left over from radiation treatment for squamous cell carcinoma, a common form of skin cancer.

Over the course of her racing career, Thompson has raised more than $100,000 for cancer organizations, the Charlotte newspaper noted.

Her achievement Sunday displaces Gladys Burrill as the oldest woman to complete a marathon. Burrill was 92 years and 19 days old when she finished the 2010 Honolulu Marathon, the AP noted. Thompson is 92 years and 65 days old, race organizers said.