Karen Jones, an 18-year-old home grown product, eagled the 20th hole at Argyle yesterday to gain the final of the Women's District Golf Association championship.

Chris Epperly of Army Navy sent the match into extra holes by winning the 18th with a birdie.

Sharon Briggs, a weekend golfer from Montgomery Village who works as an administrative assistant, eliminated tournament favorite Ruth Meaders, also Army Navy, 3 and 2. Briggs will play Jones for the title starting at 9:54 this morning.

Epperly gained an extension when she won the par-5 18th with a birdie after Jones' drive went into the trees. The two women halved the first extra hole with pars and on the par-5 second hole, the 20th in the match, Jones was on the green in two and sank a 22-footer for the victory.

Epperly was in front only once, after the first hole. Jones made the turn 1 up and then birdied the 10th hole. Epperly cut the lead back to one when she rolled in a 15-footer on the short 13th hole. The two golfers halved the next four holes until Epperly evened the match on the 13th. Each had 74, one over women's par.

Jones, playing in this tournament for the first time, was third in the Orange bowl junior championships last year and has been the runner-up in eight other tournaments. "Very depressing," she said, "but I hope to break the spell against Briggs on Friday."

Briggs, a veteran tournament player, was runner-up in this tournament in 1977 to Sue Keeney, the same year Briggs won her club championship.

Briggs was two holes up after nine holes over Meaders, who kept missing putts from within six feet. And Briggs proved too steady on the back. She birdied the 11th, but Meaders brought the margin back to two with a birdie on the 13th.

Meaders missed a six-footer for a bogey on the 10th as briggs increased her lead to 3 up. Meaders parred the short 13th to cut the margin back to two. But Briggs again took a 3-up lead on the 14th when she parred. The next two holes were halved.