Mo Farah joined Usain Bolt with a third straight double in individual events at global competitions since winning the 5,000 and 10,000 meters at the London Olympics.
After defending the 10,000 title on the opening day of the world championships last weekend, Farah had a relatively easy race in the 5,000 on Saturday.
Hanging back in last place for the first two kilometers, Farah then quickly moved up.
When Caleb Ndiku sought to sprint away over the last lap, Farah kept the Kenyan in check and beat him in the finishing straight.
"It is amazing," Farah said. "I worked so hard for it."
Ever since the 2012 Olympics, Farah has been unbeatable over the long distance races and has six major gold medals to show for it.