"Ecuador joins a number of other nations of South America which have included Sputnik V in their coronavirus vaccine portfolios," Kirill Dmitriev, the head of RDIF, said in a statement.
Earlier, television stations Ecuavisa and Teleamazonas published the results of the Cedatos exit poll that gave Lasso almost a 6.5 percentage point lead over Arauz.
Lasso has tried to soften his conservative image by promising to fight discrimination on the basis of sexual orientation and boost protection of animal rights.
The money came from a 10-billion-euro rescue fund created by the government of Socialist Prime Minister Pedro Sanchez to help strategically important firms hit hardest by the pandemic.
President Lenin Moreno denounced the "barbarity" of the riots and said the gangs were "fighting for leadership and the trafficking of drugs throughout" Ecuador.
To emerge victorious, a candidate must take half of the votes cast, plus one, or at least 40 percent with a 10 percentage point advantage over his nearest rival.