St Mirren avoided being the victims of another giant killing as they eased past Dumbarton 3-0 to reach the fifth round of the Scottish Cup.

Saints dominated from the outset and carved out the first chance of the game with just three minutes on the clock when Mark Corcoran whipped a cross in from the left and Billy Mehmet dragged his shot just wide of the upright.

Dargo then found himself one on one with David Crawford but the Dumbarton goalkeeper stood tall to block the point-blank effort before Mark Canning cleared the danger.

David Van Zanten cross though allowed Corcoran to open the scoring on 17 minutes with a close-range drive.

David Barron's thunderous 25-yard drive doubled the lead seven minutes before the break and the tie was over with 20 minutes to go when Mehmet lashed home Saints' third of the day from the edge of the box.