First of all, we would like to stress the fact that the Sharia permits all things that are beneficial to the body and it prohibits all things that may cause damage or harm to it. The Prophet (peace and blessings be upon him) is reported to have said: ‘Your body has rights over you.’(Reported by Al-Bukhari)
If sports are free from things which are prohibited in Sharia, then practicing those sports is beneficial and permissible.
Focusing more on the Islamic stance on wrestling, we would like to cite for you the following fatwa issued by the late Sheikh Ahmad Ash-Sharabasi, professor of Sharia at Al-Azhar University:
“Islam does not oppose wrestling practiced to enhance and improve physical fitness and self-defense. If wrestling is governed by a regulatory law that protects human rights and saves the lives of wrestlers from any dangers and protects them against any maims, then such kind of wrestling is permissible, and there is nothing wrong with it.
It is reported that the Prophet (peace and blessings be upon him) once wrestled with a man called Rukanah who was well-known for his strength, throwing him to the ground more than once. (Reported by Abu Dawud)

In another report of this incident, the Prophet (peace and blessings be upon him) started wrestling with him. As the fight was hard, Rukanah said, ‘A sheep for a sheep.’ (This must have occurred before the prohibition of gambling, or perhaps the Prophet (peace and blessings be upon him) did not accept the bet and hence did not enforce its terms.) The Prophet (peace and blessings be upon him) then wrestled him down. The man challenged the Prophet (peace and blessings be upon him) again, but was wrestled down again by the Prophet (peace and blessings be upon him). Being floored again for the third time, the man said, ‘What shall I tell my wife? One sheep was eaten by the wolf, one ran away, but what about the third’. Then the Prophet (peace and blessings be upon him) said, ‘We are not going to defeat you and take something from you as well. Take your sheep!’

It is clear from the aforementioned evidence that wrestling, which is practiced within the norms of legitimate sports, and physical training is permissible, because if such wrestling is haram, the Prophet (peace and blessings be upon him) would not have practiced it.

However, if there is no law that regulates the sport to the extent that practicing it is no more than a barbaric act, then such form of wrestling is prohibited in Islam. Also, practicing wrestling becomes impermissible if it causes damages or wounds.
The aforementioned ruling is deduced from the juristic rule stating that harm should be removed, and on the other rule stating that fending off harm takes priority over procuring benefit.
Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, adds:
“Islam’s position on sports and games is determined by weighing and comparing all relevant benefits and disadvantages. If there are tangible benefits in a sport or game, then it is deemed to be permissible, or even recommended; if, however, there is more harm than benefit to be accrued from a sport, then such as sport may very well be considered forbidden. Also, while comparing benefits and disadvantages, Shari`ah lays greater emphasis on the removal of any perceived harm over any presumable benefits.
Wrestling, during the time of the Prophet (peace and blessings be upon him), involved using physical fitness and skill to overcome an opponent; such skills were, and are, quite desirable, or even essential, for the purpose of self-defense. Also, training to fine tune or build muscles is encouraged. Wrestling falls under this category.”