TOKYO, Sept. 20 (Xinhua) -- Kenya's Beatrice Chebet and Spain's Maria Perez both completed golden doubles at the World Athletics Championships on Saturday, winning the women's 5,000 meters and 20-kilometer race walk respectively. Chebet, the 25-year-old Olympic champion who broke the world record earlier this year in Eugene with 13:58.06, added the 5,000m crown to her 10,000m title in 14:54.36. For Kipyegon, it was her sixth gold in six world championships. She has the world record, she is very tough to beat." "I have competed in five world championships and this is my fourth medal.