Smith got the opener when he lobbed the visiting keeper before Killie were reduced to 10 men, one of their defenders apparently harshly sent off after he and Smith went for the ball.
Smith got the second before McGinn scored from a free-kick and then straight from a corner, Michael Fulton finishing things off with the fifth.
A fine win for the kids, even if they wre helped by a questionable red card. Hopefully the first team can follow in their footsteps on Saturday.
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