Goals from Connor Tomlinson, Ollie Swain, Charley Sanders (2) and Danny Setchell ensured the semi-final success over the UCL Premier South side.
Gary Setchell’s side will now face Leighton Town, fourth in the Spartan South Midlands Premier Division, at Luton Town’s Kenilworth Road ground on April 26. Leighton beat Biggleswade FC 3-0 in their last-four game.
Leaders Eagles stay four points ahead of Berkhamsted in the Southern League Division One Central title race, after adding three more points from a 3-0 win at home to relegation-threatened Colney Heath on Saturday.
Lewis Miccio opened the scoring after half an hour,
with Rene Howe making it 2-0 just after the hour and Sanders (pictured) rounding things off with 20 minutes to go.
It’s local derby day on Saturday when Gary Setchell’s side make the short trip to Kempston Rovers, who are third from bottom. Rovers were beaten 3-1 by Berkhamsted last Tuesday, while Eagles remain unbeaten in 17 games.
They are back at the Eyrie on March 26, hosting fourth-placed North Leigh.