A decorated Navy combat pilot received a 30-day suspended jail sentence after pleading guilty in Alexandria Circuit Court to assault and battery on a woman he met on a date.

The plea Thursday of former lieutenant commander Christopher W. Gilluly, 33, ended a nearly two-year legal struggle that included a four-day trial in December 1978 at which Gilluly testified that he bound and beat the woman with her consent as part of a sexual encounter but denied raping her.

Gilluly was convicted of assault and battery but acquitted of the more serious charge of rape. He received a six-month jail sentence and a $1,000 fine after the first trial, but the sentence was delayed while he appealed.

Last June the guilty verdict was overturned by the Virgina Supreme Court because of a defect in a search warrant. Gilluly was scheduled to stand trial for a second time next month, but he entered the guilty plea to the misdemeanor charge two days ago.

"This was a financial decision, " attorney Stephen A. Armstrong, representing Gilluly, said yesterday. "It cost $37.50 to enter this plea, and would have cost more than $10,000 to go to trial. He admitted nothing. This is tragic. He has gone through hell. It has ruined his career."

The former fighter pilot, who won 12 medals for his air combat missions, could have been sentenced to up to 12 months in jail and fined $1,000 for the guilty plea. The 30-day suspended sentence was imposed by chief Alexandria Circuit Court Judge Wiley R. Wright Jr., who sealed the court record after the sentencing. City Prosecutor John E. Kloch said the record was sealed to protect the woman and Gilluly.

At the first trial both Gilluly and the woman testified they had gone to his Alexandria apartment at 3 a.m. to practice disco dancing. The woman testified Gilluly forced her into the bedroom after she resisted his advances, tied her to the bed and beat her. She also claimed he raped and sodomized her.

Gilluly testified the woman had consented to the beatings, but denied any sexual intercourse with her.