One of the major open problems of neutrino physics is mass ordering (MO). We discuss the prospects of measuring MO with two under-construction experiments T2HK and JUNO. JUNO alone is expected to measure MO with greater than 3 sigma significance as long as certain experimental challenges are met. In particular, JUNO needs better than 3% energy resolution for MO measurement. On the other hand, T2HK has rather poor prospects at measuring the MO, especially for certain ranges of the CP violating parameter delta(CP), posing a major drawback for T2HK. In this article we show that the synergy between JUNO and T2HK will bring twofold advantage. First, the synergy between the two experiments helps us determine the MO at a very high significance. With the baseline setup of the two experiments, we have a greater than 9 sigma determination of the MO for all values of delta(CP). Second, the synergy also allows us to relax the constraints on the two experiments. We show that JUNO could perform extremely well even for an energy resolution of 5%, while for T2HK the MO problem with bad values of delta(CP) goes away. The MO sensitivity for the combined analysis is expected to be greater than 6 sigma for all values of delta(CP) and with just 5% energy resolution for JUNO.