Only a handful of people were able to watch the tie because of the coronavirus
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.
Hungary’s tie against Belgium was the only qualifier to go to a deciding rubber, with Marton Fucsovics defeating Ruben Bemelmans 6-7 (7) 6-4 6-2 to complete a comeback from 2-1 down for the hosts in Debrecen.
Sweden secured a 3-1 win over Chile as 21-year-old Mikael Ymer recorded a three-set victory against Alejandro Tabilo.
Austria were without their number one Dominic Thiem, but Dennis Novak beat Pablo Cuevas 2-6 6-3 6-4 after Jurgen Melzer and Oliver Marach had edged a tight doubles to seal a 3-1 win.
Last year’s quarter-finalists Germany saw off Belarus 4-1, while Alexander Bublik won both his singles matches to help Kazakhstan to a 3-1 success over the Netherlands.
Marin Cilic lost just one game against Sumit Nagal to give 2018 champions Croatia a 3-1 victory over India, while John Millman won three tie-breaks against Thiago Monteiro as Australia beat Brazil 3-1 in Adelaide.
Italy against South Korea was also played behind closed doors in Cagliari, the hosts easing to a 4-0 victory.