Sifan Hassan, a two-time track Olympic champion who had never run a marathon, prevailed in London over a formidable field of champions who were all experts over 26.2 miles.
That alone would be extraordinary, but early on it appeared as though Hassan would have to withdraw.
She was dealing with a hip ailment, limping, and at one point pulled over to the side of the road to stretch it out as her competitors moved ahead of her.
“She needs to stop,” Britain’s marathon world champion Paula Radcliffe said on BBC TV.
“Somebody needs to give her some advice to step off and stop trying to run on.”
But Hassan, a former refugee who left Ethiopia for the Netherlands as a 15-year-old, did not stop.
She continued, reeled in the Olympic marathon champion and last year’s winner in London before sprinting for glory on The Mall.
“To outkick them is remarkable,” Radcliffe said.
“It’s not just winning it, it’s the way she was out of contention and yet she fought back to beat the Olympic champion, the defending champion.
“She is an inspiration and that is just phenomenal.”
Before the race the 30-year-old was not talking like someone confident of winning a marathon.
She admitted she was “scared” of competing over the distance. She said she cried at the prospect on the morning of the race.
“Sometimes I wake up and it is like ‘why the hell did I decide to run a marathon?’ But also, at the same time, I am very curious [about how I will perform],” she said in the pre-race news conference.
Hassan’s build-up was also impacted by the holy month of Ramadan which, as with others who follow the religion of Islam, meant abstaining from eating or drinking during daylight hours.