BEIJING:  Mare Dibaba gets asked all the time if she's related to Ethiopian great Tirunesh Dibaba. She's not.

Runs a lot like her, though. Especially when a title is on the line.

Mare Dibaba captured the first women's marathon gold for Ethiopia at the world championships Sunday, holding off Helah Kiprop of Kenya in a race that was settled by a 100-meter sprint.

The 25-year-old Dibaba patiently waited for the right time to make her move, constantly checking her watch before breaking away in the shadow of the Bird's Nest. Dibaba finished in 2 hours, 27 minutes, 35 seconds, edging Kiprop by one second in the closest women's marathon finish ever at the worlds. Eunice Kirwa of Bahrain earned the bronze.

"No pace is bad. When everybody goes, you go," Dibaba said through a translator. "I had to wait for it. Finally, I kicked."

It's been hot and humid all week in Beijing, but turned cooler for the race. There was even cloud cover. The air quality wasn't ideal, though, with the race starting at the "moderate" level and staying in the "unhealthy for sensitive groups" range until the finish.

Two-time champion Edna Kiplagat was in contention until the end but faded to fifth place.

With the stadium in sight, Dibaba decided to make her move. Just after entering the tunnel — about where Usain Bolt started the 100 meters — she separated from Kiprop, who couldn't answer that speed.

Asked if Dibaba was simply stronger at the end, Kiprop responded: "Yeah."

Dibaba certainly has a fitting name for a champion and often gets asked if she's related to Tirunesh, who's captured five career gold medals at the worlds. Or even Genzebe Dibaba, the younger sister of Tirunesh and world-record holder in the 1,500.

They're from different places, but Tirunesh Dibaba is her biggest influence.

Turns out, she has that familiar Dibaba kick, too, even if they're not related.

"My energy was there," Mare Dibaba said. "I was so confident, purely confident."

Around the two-hour mark, Kiplagat said something to her Kenyan teammates and they began to pick up the pace. A pack of a dozen runners was thinned to six.

That group included not only the Kenyans, but Dibaba and Kirwa, who is Kenyan and started to compete for Bahrain in 2013. Soon after, Kiplagat dropped back, too.

"I had the confidence because my last lap is fast," Dibaba said.

American runner Serena Burla was with the lead group until late in the race, when she lost touch and wound up 10th.

In 2010, Burla had a tumor removed in her leg wasn't sure if she'd ever run again. Last week, her grandmother died.

"You have to live each day to the fullest," said Burla, who has a scar behind her right knee. "A great reminder to do what you love and do what you love well."