Bolt has been untouchable on the blue track at the Luzhniki stadium, winning the 100 last weekend and then becoming the first man to take three successive 200 metres titles.
There should also be a third medal for Jamaica's double world champion Shelly-Ann Fraser-Pryce in the women's relay although Olympic champions the U.S. start as slight favourites, even minus Allyson Felix who tore her hamstring in the women's 200 final on Friday.
With the fans finally filling the stadium in numbers, the championships could end on a noisy high with Russia's Olympic gold medallist and defending champion Mariya Savinova and Ekaterina Poistogova in the women's 800 metres final.
The women's javelin, men's triple jump and men's 1,500 metres are the other medals left to be decided.
(Writing by Alison Wildey; editing by Justin Palmer)
