Manufacturer’s encroachment and retailer’s reselling strategies are prevalent in the contemporary global supply chain operations.  In this backdrop, the simultaneous or sequential decision-making of the supply chain members can play an instrumental role in their pricing decisions and profitability. This issue motivates us to develop a game-theoretic model for a dyadic supply chain comprising one manufacturer and one retailer, where the manufacturer adopts an encroachment strategy, i.e., selling product through its direct channel apart from the other retailer’s outlet and the retailer follows a reselling strategy, i.e., setting a markup over the manufacturer’s wholesale price of the product and selling it to the market. Here, we consider the quantity competition between the manufacturer and the retailer. Using a game-theoretic approach, we investigate how the supply chain members’ simultaneous and sequential decision-making impact the optimal supply chain members’ quantity decisions and profitability, along with the consumer surplus. The comparative analyses signify that sequential decision-making leads to higher supply chain members’ profits and consumer surplus than simultaneous decision-making.