Games have emerged as one of the most popular applications on mobile platforms. Recent platforms are now equipped with Heterogeneous Multiprocessor System-on-Chips (HMPSoCs) tightly integrating CPUs and GPUs on the same chip. This configuration enables high-end gaming on the platform but at the cost of high power consumption rapidly draining the underlying limited-capacity battery. The HMPSoCs are capable of independent Dynamic Voltage and Frequency Scaling (DVFS) for CPUs and GPUs for reduction in platform’s power consumption. State-of-the-art power manager for mobile games on HMPSoCs oversimplifies the complex CPUGPU interplay. In this paper, we develop power-performance models predicting the impact of DVFS on mobile gaming workloads. Based on our models, we propose an efficient power management strategy and implement it on an Odroid-XU+E mobile platform. Measurements on the platform show that our power manager provides on average 20% increase in performance per watt when compared to the state-of-the-art.