Forres set up a home North Cup quarter-final tie at Halkirk next Saturday thanks to Owen Paterson’s last-minute winner against the Lilywhites, who finished the game with nine me.
Mechanics manager Charlie Rowley said: “Clach had two players sent off which didn’t help them, but we were stretched for numbers. We had two youth development players on the bench along with our coach, Charlie Brown.
“We threw Charlie on as a last throw of the dice at 1-1. By that time they were down to nine and it was Charlie who provided Owen with the pass for our winner.
“We didn’t play particularly well when they were down to nine men but the most important thing was to get through, which we did.”
Clach assistant manager, Brian MacLeod, said: “It certainly didn’t help our cause having both Daniel MacLennan sent off for a straight red and goalkeeper John Campbell also being dismissed for two yellow cards, but the referee didn’t do us any favours.”
Clach took the lead in the seventh minute with a superb left-footed volley from Liam Shewan, but the Can-Cans levelled three minutes from the break, Stuart Soane notching his 24th of the season.
MacLennan saw red for a challenge on Alan Pollock before goalkeeper John Campbell joined him for an early bath after picking up a second yellow card for dissent.
In the 90th minute Brown set up teenager Paterson to score the winner.