He left with an aching hip and, far worse, an aching heart.
Keflezighi was back Sunday, wiping away tears after the New York City Marathon -- for his historic victory for his country, for his recovery from an injury he once feared might end his career.
The 34-year-old Keflezighi became the first American man since 1982 to win the NYC Marathon. His time of 2:09:15 was a personal best.
"It can't get any better," he said.
Derartu Tulu of Ethiopia was the women's winner, on a day when a record field of nearly 44,000 started the 40th edition of the race.
Tulu won in 2 hours, 28 minutes, 52 seconds. Two-time defending champion Paula Radcliffe fell back to fourth, hobbled by tendinitis behind her left knee.
Keflezighi won silver at the 2004 Olympics, the first American man to medal since 1976. Sunday's race proved how much depth the U.S. now boasts: With the event doubling as the national championship, six Americans finished in the top 10 for the first time since '79.
Eleven years ago, Keflezighi wrote a letter to Alberto Salazar, the last U.S. man to win in New York. Salazar was working with Nike, and Keflezighi told him that for U.S. distance running to thrive, athletes needed the funding to allow them to train full-time. That same year, Keflezighi became an American citizen. He was born in the East African nation of Eritrea, growing up in a hut with no electricity. Soldiers would surround his village, looking for boys 12 and older to drag off to war.
When he was 10, his family moved to Italy; two years later, they came to the United States. Keflezighi began running in junior high in San Diego, then went on to star at UCLA.