Kenyan-born Bahraini Rose Chelimo edged veteran Edna Kiplagat to win the women's marathon at the IAAF World Championships on Sunday.
Kiplagat hit 40km a second ahead, but Chelimo kicked in the last 2km to win Bahrain's first medal in the event in 2hr 27min 11sec.
Kiplagat, a two-time previous champion in 2011 and 2013, claimed silver seven seconds adrift, with American Amy Cragg taking bronze.
"I was not expecting to win," said Chelimo, who transferred allegiance to Bahrain in 2015.
"I tried my best and I managed to become the world champion.
"Edna Kiplagat is strong. At 35km I pushed, after some time Edna came and I said to myself 'let her go', I already accepted to be second. But then I caught her, I was encouraged and thought 'maybe I can try' and I succeeded."
Kiplagat acknowledged that the final run-in was "the most difficult".
"All the way I worked so hard, so the last 3km was too long for me and slightly uphill. I think I was too tired after the previous sprints," the 37-year-old said.
"Hopefully my body will get stronger and I keep training so I can come back and go for a major gold again.
Cragg said it felt "crazy" to have medalled.
"My coach has been putting it my head that this is a potential medal and something I can do," she said.