Sayyiduna Samurah bin Jundub (may Allah be pleased with him) said: Every year the boys of the Ansar were presented before the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) would enlist with him whichever of them had reached maturity. He said: I too was presented one year. He (peace and blessings be upon him) enlisted one boy with him and sent me back. I said: "O Messenger of Allah (peace and blessings be upon him), you have enlisted him and sent me back, yet if I were to wrestle him I would throw him down." He (peace and blessings be upon him) said: "Wrestle him." I wrestled him and threw him down, so he (peace and blessings be upon him) enlisted me with him too.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السبق والرمي / 19760
Sa'id bin Jubayr (may Allah have mercy on him) said: The Messenger of Allah (peace and blessings be upon him) was at a place called al-Batha' when Yazid bin Rukanah, or Rukanah bin Yazid, came to him (peace and blessings be upon him). He had some goats with him. He said: "O Muhammad (peace and blessings be upon him), will you wrestle with me?" He (peace and blessings be upon him) said: "If you lose, what will you give?" He said: "A goat." He (peace and blessings be upon him) wrestled him, threw him down and took a goat. Rukanah said: "Again." He (peace and blessings be upon him) said: "If you lose, what will you give?" He said: "Another goat." This happened several times. He said: "O Muhammad, no one has ever put my back to the ground, that is, thrown me, yet you have thrown me." He became a Muslim, and he (peace and blessings be upon him) returned his goats to him.
It is a good mursal (report missing the Companion); it has also been narrated connected through another chain, but that chain is weak. And Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السبق والرمي / 19761