BOSTON — Something unusual happened when Meb Keflezighi, far ahead of his competitors, began passing some of the elite women who had started before the men on Monday in the Boston Marathon. As he charged by, many of the women — exhausted and in pain — cheered him on.

Three years ago, Keflezighi was widely considered to be on the downward slope of his marathon career. He had lost his Nike shoe sponsorship. His best running days were probably behind him.

Keflezighi managed to find a new shoe sponsor, but the company was not exactly a powerhouse in the running world. He was picked up by Skechers, a brand primarily known for skateboard shoes.

On Monday, Keflezighi, who turns 39 in two weeks, introduced the running world to Skechers as he and his red and silver sneakers stepped across the finish line of the Boston Marathon a good 11 seconds ahead of anyone else.