A former Hammond High School wrestler testified yesterday in Prince George's County Circuit Court that he was hypnotized and made to perform sex acts during a private coaching session with former St. John's College High School wrestling coach Michael John DeSarno, who is charged with child abuse.

DeSarno was arrested last December after two teen-agers told county police that he forced them to perform sex acts at his Beltsville apartment in 1983 and 1984.

DeSarno, who has been free on personal recognizance, is being tried on one count of child abuse. If convicted he faces a maximum sentence of 15 years.

Before prosecuting attorney Thomas McManus rested his case yesterday, the former wrestler, who attended clinics operated by DeSarno during the off-season, testified that in addition to sessions that DeSarno conducted at the St. John's gym, the coach often invited him and other boys over to his apartment so they could "practice wrestling techniques." The alleged abuse took place during a session at DeSarno's apartment.

The wrestler, a recent high school graduate, told jurors that on one occasion in 1983 DeSarno hypnotized him and told him to disrobe. He said he then complied with DeSarno's request that he perform a sex act.

The youth said that he "wondered what this had to do with wrestling -- was it really helping me," but he said he hesitated to tell his parents or police because he was embarrassed. Defense attorney Joseph DePaul is expected to present his case today.