In 2014, the three main organizations of domestic workers in Chile achieved an important legal modification (Law No. 20,786) that, at least formally, improves their employment and work conditions, making the labor of these workers less precarious. The present article seeks to explain this victory of domestic workers, given their low structural and associative powers. Through the analysis of 13 in-depth interviews with unionized and non-unionized workers, a focus group with members of the SINTRACAP union, press review and legislative history, and participant observation (2017-2019), it is concluded that SINTRACAP developed three types of strategies unions in the period 2010-2014, which allowed them to achieve the aforementioned reform: (1) establishment of alliances with other organizations and unions of domestic workers, (2) mobilization of international institutions to put pressure on the Chilean State and (3) generation of alliances, exchanges and some pressure on political actors to approve reforms in their favor. The mobilization of these "external" powers has allowed the organization to overcome its weakness and effectively represent the interests of the domestic workers, but also, it has relied on these external powers, avoiding the development of its own associative powers.