BOSTON (WPRI) — One of the biggest fans at the Boston Marathon has officially crossed his final finish line.

Spencer the golden retriever, who is best known for holding Boston Strong flags in his mouth along the marathon route, died Friday at the age of 13 after a long battle with cancer.

His owners, Rich and Dorrey Powers, confirmed his passing on Facebook.

“He has been an inspiration to hundreds of thousands of people. He was an angel on earth,” the post read. “Any who had the good fortune to actually meet him in person can attest that when you touched him he emitted pure energy and light.”

In 2022, Spencer was named the official dog of the 126th Boston Marathon. His owners said it was a question if he would even make it to the 2021 and 2022 races because of his health.

“Spencer has overcome some severe medical challenges over the past several years. We thought we would be lucky to have him for an extra month,” his owners said. “Spencer was not ready to give up and with the love and positive energy sent to him by hundreds of thousands of fans, he beat the odds and gave us 28 months.”

In September 2022, he was again diagnosed with inoperable cancer and his owners didn’t know if he would make it to the next race.

To honor Spencer and keep his memory alive, a giant portrait was unveiled last month. He was also awarded a commemorative 2022 marathon medal by the Boston Athletic Association.

Following his passing, the Boston Marathon posted on Facebook that Spencer will forever be the “Official Dog of the Boston Marathon” rather than for only one race.

“Spencer will forever be in our hearts and we are devastated with his passing,” his owners said.

The 127th Boston Marathon is set for April 17.