Mike Quarry showed the wear and tear of an 80-fight career last night as he lost a unanimous decision to Blueford Spencer, a little known Baltimore pro, in the feature attraction of a seven-card program at Crystal City.

Quarry, 31, rarely was the aggressor and appeared arm-weary by the sixth round in the lackluster fight that stirred little emotion from the estimated crowd of 800 at the Hyatt Regency ballroom. Two judges scored the fight 79-75 and the third voted 78-76.

Blueford (10-3-1) was not particulary impressive, but he didn't have to be to stay ahead of Quarry, who began his career at age 18 in 1969. Quarry often seem content to stay on the ropes and absorb what little punishment his opponent could inflict.

Quarry once owned a 36-0 record, but that was before he was knocked out in 1972 by Bob Foster, then the light heavyweight champion fighting out of Washington. Quarry, the younger brother of Jerry, a journeymen heavyweight, has been struggling in recent years and just returned from a series of fights in Argentina. His record is 63-12-6.

O.C. Harper of Washington avenged a loss to Scott (The Manassas Mauler) Farmer in the junior welterweight cofeature, winning on a technical knockout at 2:54 of the fifth round.

Farmer, 24, won the lightweight title of Virginia with a one-round knockout in his last fight. He was badly cut over the left eye in the third round and after he twice was examined by the doctor at ringside, the fight was stopped despite his protest.

John Taylor, a 144-pounder from Baltimore, upset Mike (The Mongoose) Hess of Alexandria on a split decision in the featured six-round karate match. Hess (15-2) was badly cut over the left eye in the second round.

In the other karate match, Joe (Thunder Foot) Cooper, 181, of Alexandria knocked out C.D. Williams of Hampton, Va., in 1:50 of the fourth round.

In the opening match, David Todd, 20, of Oxon Hill won his first professional fight when his bout with Tobie Smith was stopped after 2:45 of the second round. Mike James, 150, of Springfield arose from the canvas in the second round to win a unanimous six-round decision over Marvin Crawford of Falls Church in the next match. 6-Bout Card Tonight

A six fight card will be held tonight at the Hyatt Regency hotel at New Jersey Avenue and D Street NW.

Middleweights Ricky Perry and Leon Martinez headline the recently revised program that originally included heavyweights James Broad and James Reed.