Coldstream opened very brightly as the visitors took time to settle but after seven minutes a Forres cross found centre Scott unmarked and he confidently rammed the ball home.
After 12 minutes a slick move involving Doohan, John Crawford, Coldstream's two consistently best performers this season, and Zavaroni led to Irvine having a chance which was not to be.
The Streamers were lively up front, causing the Mechanics' defence some concern but the latter operated the offiside trap to good effect.
After 20 minutes, the visitors increased their lead when a corner wasn't properly cleared and Scott notched his second goal. Walters in the Coldstream goal was called into action with several nifty saves as the visitors looked to put the match beyond Coldstream's reach.
After 22 minutes, the Mechanics' notched their third goal, a somewhat fortuitous one when a deflected cross/come shot by Whyte dropped into the corner of the Coldstream net.
The second half largely belonged to Coldstream with John Crawford notching a goal after 78 minutes from a Doohan corner.
Earlier in this half, a Hebdon screamer from 30 yards could have taken the Forres net off but it just rocketed by. Had this gone in, it could have been interesting. Irvine of Coldstream was sent off after stamping on an opponent in front of the referee and it was a straight red card.
In essence Coldstream fought hard in this tie, they pose danger up front and from the wings but have not as yet solved the leaky defence.