Duff was second in the medalist standings with a 2-over-par 35-39-74, one shot behind Middletown's Alex Hoffman. Starliper posted a 7-over 40-39-79 and Fairley also shot 79, his career best. The boys played the Black Rock course at 6,383 yards.
Among the girls, Lee led a group of five qualifiers with a 2-over 74 while Spessard punched her ticket with an 89.
"My goal at the beginning of the year was to help my team make it to the states," said Duff. "But now, I'm on my own. My goal is to shoot 150 or better at states."
Duff had three birdies, but the highlight of his day came on the 9th hole, a 408-yard par-4. His drive left him in position for a pitching wedge from 120 yards out, and his approach hit the pin and dropped into the cup for an eagle.
A senior, Duff will be making his second state appearance at College Park.
"This overshadows some of the earlier disappointments in the season," said Duff, who came up short in the county tournament and to Lee during the junior golf season.
Meanwhile, Lee zapped the girls field by 11 strokes and tied Duff for the second-best overall score.
Playing from 5,495 yards, Lee played the front nine in even-par 36 before running into trouble with two bogeys and a double bogey in the first four holes on the back. She straightened things up with birdies on the par-3 15th and par-4 18th.
"I had some tee shots into trees and left some wedges short," said Lee of her bogey trouble.
The Smithsburg sophomore has experienced plenty of tournament action this year, but the trip to College Park will be her biggest to date.
"I think I'll be nervous," she said. "It will be an experience. I'll need to play a practice round."
Fairley came through in unexpected fashion, especially after a practice round Monday in which he said he was "not good at anything."
He also dropped in a key eagle, which was the difference in making the grade. On the 471-yard par-5 third hole, Fairley hit a 300-plus-yard drive and had a 160-yard 6-iron to the green. Fairley got on top of the iron shot, but got it within 7 feet of the hole and drained the putt.
"Today was a huge turnaround," he said. "Yesterday I went home and just said a prayer. Whatever happens, happens."
Starliper, a senior, avoided a late collapse despite a double bogey on his last hole.
"This makes the year," he said. "Ever since the counties (mid-September) I've played bad golf, but today helps.
Gossard, a freshman, had 46 on the front a a 43 on the back as she matched her best-ever round at Black Rock.
"I feel nervous but confident," she said of making the states.