Holders Fraserburgh will travel to Keith or Huntly in the semi-final of the Evening Express Aberdeenshire Cup after edging out Inverurie Locos at Bellslea.
Goals from Paul Young and Ryan Cowie sealed the tie against a Locos side which seldom got out of second gear until Kieran Shanks pulled a goal back 14 minutes from time.
Broch boss Mark Cowie paid tribute to former Aberdeen youngster Lewis Duncan, who created both goals. He said: “We knew what we were getting when somehow we managed to take young Lewis here after he was released by Aberdeen – he’s a local Broch lad and a really talented kid.
“He’s the type of player who might do nothing for 10-15 minutes then he produces a little bit of magic, as he did for both of our goals.
“I don’t think any other player on the park today could have played that ball in for Paul Young to score our early opener.”
Fraserburgh opened the scoring in the third minute. Teenager Duncan brilliantly played in Young who made no mistake from eight yards.
Locos were awarded a penalty kick in the 18th minute when Broch keeper Paul Leask bundled over Shanks in the box and referee Liam Duncan immediately pointed to the spot.
Andy Hunter stepped up to take the penalty, but his weak effort was too close to Leask who dived to save easily. Within a minute of the restart Fraserburgh doubled their advantage, danger-man Duncan was again the creator and Ryan Cowie provided the killer touch to the midfielder’s cross from close-range.
On the hour Lewis Davidson almost added another, but the full-back’s drive from the edge of the box rebounded off the upright with Reid beaten.
With 20 minutes to go Fraserburgh were reduced to 10 men when man-of-the-match Duncan was shown a straight red-card for a two-footed challenge on Nathan Meres.
In the 76th minute, Locos pulled one back when Shanks turned on a sixpence and fired home to set up a grandstand finish, but the home defence stood firm to progress to the semi-finals.
With Locos’ manager Andy Low absent, as his wife was about to have a baby, his assistant Steven Park admitted his side were caught cold at the start of both halves.
He said: “We didn’t start well, although the officials played a part in their opening goal, when it was a clear Locos throw-in and it was given to the Broch.
“Our guys need to be switched on to things like that, and play the whistle. Today we stressed the shape of the team and the need to be disciplined.
“When you play teams like Brora and the Broch, you need to pay them a bit of respect and know when to press at the right time, as they play the game at 100mph and are in your face from the first minute to the last.”