Records of the Three Kingdoms
Xiahou Yuan, courtesy name Miaocai, was a younger clansman of Xiahou Dun. He joined Cao Cao at the start and at one time handled grain transport. His main work was then in the west: remnants of Ma Chao, Song Jian, and Han Sui, and in 215 the defeat of Zhang Lu, which gave Hanzhong to Cao Cao. He moved fast. The biography uses a camp saying — five hundred li in three days, a thousand in six — to mark that speed.
Cao Cao warned him that a general must sometimes be willing to hold back and must not trust to courage alone. In 219, while Liu Bei fought for Hanzhong, Xiahou Yuan was routed at Dingjun Mountain. His own biography says Liu Bei’s army killed him. Huang Zhong’s biography says Huang Zhong beat the drums, advanced, and cut him down in one engagement. Zhang He rallied the remnants. Cao Cao then came in person and still did not retake Hanzhong.
Romance of the Three Kingdoms
The novel makes Dingjun a duel staged by Fa Zheng: he watches the ground, and Huang Zhong comes down the hill. Xiahou Yuan leaves camp to repair the abatis. Huang Zhong arrives at once, and the blade falls.
The reliance on courage, and Cao Cao’s warning, are both used. The man who kills him is Huang Zhong, which matches Huang Zhong’s biography. The exchange of speeches and the lure out of camp are the novel’s expansion.
Reference: Wikipedia · Xiahou Yuan