Caleb Ndiku has vowed to give long-distance rival Mo Farah a "battle" in this afternoon's 5,000m final at the World Athletics Championships in Beijing.

Five-time world champion Farah goes into the Bird's Nest stadium vying for an unprecedented 'triple-double' success after already retaining his 10,000m title earlier in the competition.

Kenyan Ndiku, who has missed much of the season through injury, is expected to pose most threat to the Briton's claim, and the 22-year-old - who won Commonwealth gold over this distance last summer - is hopeful that his body allows him to derail his rival's history bid.

"My weight is reduced, my body is feeling great," he is quoted as saying by The Guardian.

"All I know is that I have trained well but this year I have not done many races, so it is hard to be sure. But if my body and God allow me, I will give Farah a battle."

Farah, who finished second in his heat behind Ethiopia's Yomif Kejelcha, posted a qualifying time of 13:19.44, with Ndiku clocking 13:19.58 in joint third.