Entrepreneurial firms’ success is significantly influenced by their capacity to seize market opportunities. At the same time, little is known about when and how entrepreneurs’ alertness to the potential for business opportunities and how it influences their success. To fill this vacuum in the literature on entrepreneurship, the current study focused on identifying the impact that fluctuations in the degree of entrepreneurial networking cause on the relationship between three pertinent dimensions of entrepreneurial attentiveness and the success of entrepreneurial firms. Based on primary data collected from 384 entrepreneurial firms that are operating in Pakistan, using an adapted questionnaire, this study discovered that improvements in dimensions of entrepreneurial alertness have a beneficial impact on the success of entrepreneurial firms. Moreover, the moderating role of entrepreneurial networking has proved significant in the relationships. The effect size of the moderator is also significant and large. This study is also important for the sustainability of entrepreneurial firms because the more they are successful in their mission, the more they will be sustainable. Moreover, the moderating role of entrepreneurial networking that helps them in times of crisis also improves their sustainability. This study also revealed how entrepreneurial alertness works as a driver of entrepreneurial business success and how success is magnified in the presence of a higher degree of entrepreneurial networking. The theoretical, managerial, and policy ramifications of the study are explained at the end, along with limitations and recommendations for future researchers.