This research aims to use performance indicators to find out how marketing and R&D budgets work together to influence brand competitiveness. While many studies have examined the effects of marketing and R&D investment alone, very few have examined how these factors affect a company's performance, brand value, and competitive advantage. Seven years of longitudinal data, totaling 1020 observations, were collected from 145 organizations. Based on the systematic removal approach, these companies were selected from 640 listed on the Pakistan stock exchange market. We used the generalized method of moments (GMM), to examine the data. While research and development did have a small but noticeable effect, marketing had a much more significant and lasting effect on brand competitiveness (as measured by market share) when considered alone. Brand competitiveness was also found to be moderately affected by the impact of interaction between marketing expenditure and R&D investment in this study. Based on these results, companies need to invest in marketing campaigns that make use of R&D benefits if they want to enhance their brand's competitiveness. Most firms often have financial constraints, so it's wise to keep investing in marketing and R&D to be competitive in the long run.