Ecuador stunned Japan in Miki to reach Davis Cup Finals week in November.
The tie was played behind closed doors because of the coronavirus and world number 17s Japan were without key players against 27th-ranked Ecuador.
Gonzalo Escobar and Diego Hidalgo won the doubles rubbers 7-6 (7-3) 6-3 against Ben McLachlan and Yasutaka Uchiyama to complete a 3-0 victory.
Sweden, Austria and Hungary will all make their first appearance at the Finals, in Madrid from 23-29 November.
Defending champions Spain, 2019 runners-up Canada, semi-finalists Russia and Great Britain and wild cards Serbia and France were already assured of their places.