The positive impact of champions on systems implementation and adoption is well established. The term systems evangelist describes another common but less understood sponsor role beyond systems adoption. Subtle champion to evangelist role changes may hurt company performance, particularly when an executive fills the role. Through a historical case study using the capability building and entrepreneurial action model, the impact of an executive sponsor with daily IS management responsibility is examined. Beyond the champion phase, consistent with theory, the sponsor operates as a system evangelist, promoting use of a system poorly suited to its changing environment. Firm performance consequently suffers. This initial test of the theory demonstrates that system evangelists not only may, but are likely, to drive continued use of performanceimpeding systems. Strategies to limit negative evangelist impacts while preserving their benefits are presented. Finally, other executive sponsorship cases that appear to unfold similarly are identified for future study.