I won't go into too much details but the Asian country that defeated Russia in war, namely the Russo-Japanese war(1904-05) was Japan.
It was a conflict based on good military strategy. It all started because Japan wanted Korea as a province but Russia did not allow that to happen so Japan tried to negotiate to get Korea in exchange that Russia could keep Manchuria but Russia refused and negotiations broke down so Japan thought of an alternative...war.
Japan knew that Russia had a massive army but Japan had a very mobile and well trained army so they used that to their advantage. So the Japanese fleet open fired on the Russia Eastern Fleet in Port Arthur which eventually got destroyed. As Russia suffered humiliating defeats, the country thought it could beat Japan but Japans strategy proved superior so they defeated Russia in many battles. So in order to prevent a total "defeat", Russia asked for Peace (U.S as the middleman)which gave Japan some of what it wanted but not all. This caused both countries to be dissatisfied...
The USSR’s help in defeating Japan. The US wanted Stalin to attack from above during the invasion of Japan, aka Operation August Storm. This happened with the Soviet invasion of Manchuria.
