This paper studies how two high-tech SMEs exploit their cooperation with large corporate clients to develop and successfully implement their Open Innovation (OI) process (Chesbrough 2003; Brunswicker & Vanhaverbeke, 2015). Based on a case of radical innovation in the software industry, it highlights the original embedded OI strategy carried out by these SMEs) to compensate for their lack of resources (Dahlander & Gann, 2010) and to limit their innovation risks (Wynarczyk et al., 2013). Based on the analysis of an OI project involving two SMEs and a large company, our work suggests two main contributions to the literature on the implementation of OI in SMEs (Usman et al., 2018). Our first contribution highlights the original strategy of the SMEs to embed their OI project in client projects. The objective is then to exploit the capabilities of large companies (Tobiassen & Pettersen, 2018) and minimize their innovation risk while maintaining their autonomy. Our second contribution concerns the client capabilities which are materialized in their double role: a role of project director (Usman et al., 2017) and a role of collective exploration architect. These contributions suggest a new model for open innovation in SMEs where the large company client is neither positioned as an intermediary nor as an actor in the OI project. This model adapted to the exploration phase of innovation process could serve as a basis for other research work involving high-tech SMEs and large companies (Radziwon & Bogers, 2019) that are their clients, in order to enrich it and validate its relevance, particularly in other sectors. Our work suggests several managerial implications for SMEs wishing to exploit the skills of large groups to carry out their Open Innovation project. In the implementation of their embedded Open Innovation strategy, SMEs managers must select the client with which to cooperate by qualifying their capabilities (budget, availability and skills) and their experience in managing complex projects. They must also ensure that they maintain their autonomy from large companies by retaining leadership of their project (dedicated project manager and team) and their ability to exploit their innovation on their own.