The major military confrontation at Kunyang seals Wang Mang's fate in the spring of 23.

He sends his cousin Wang Yi and his prime minister Wang Xun with what he considers to be overwhelming force, some four hundred and thirty thousand men, intending to crush the newly constituted Han regime.

The Han forces are at this point in two groups—one led by Wang Feng, Wang Chang, and Liu Xiu, which, in response to the arrival of the Xin forces, withdraws to the small town of Kunyang (in modern Pingdingshan, Henan) and one led by Liu Yan, which is still besieging Wancheng.

The rebels in Kunyang initially want to scatter, but Liu Xiu opposes this measure; rather, he advocates that they guard Kunyang securely, while he gathers all other available troops in surrounding areas and attack the Xin forces from the outside.

After initially rejecting Liu Xiu's idea, the Kunyang rebels eventually agree.

Liu Xiu carries out his plan, and when he returns to Kunyang, he begins harassing the besieging Xin forces from the outside.

Wang Yi and Wang Xun, annoyed, lead ten thousand men to attack Liu Xiu and order the rest of their troops not to move from their siege locations.

Once they engage in battle, however, after minor losses, the other units are hesitant to assist them, and Liu Xiu kills Wang Xun in battle.

Once this happens, the Han forces inside Kunyang burst forth from the city and attack the other Xin units, and the much larger Xin forces suffer a total collapse.

The soldiers largely desert and go home, unable to be gathered again.

Wang Yi has to withdraw with only several thousand men back to Luoyang.

This is a major psychological blow to the Xin dynasty for which, after this point, all hope is lost.