Taylor Morgan's double helped Airdrie into the fourth round of the William Hill Scottish Cup with a 3-1 win over Brechin at the Excelsior Stadium.Morgan, on loan from Swedish side Ostersund, last scored in September but his two first-half goals were the catalyst for the Diamonds' victory against fellow Ladbrokes League One opposition.The hosts made a bright start and were ahead after just five minutes when Morgan collected a pass from Jamie Bain and fired a shot beyond Brechin goalkeeper Graeme Smith.That lead was to last only eight minutes, though, as Andy Jackson headed home Willie Dyer's cross from close range to draw the sides level.Airdrie, and Morgan, responded once more with the on-loan forward doubling his tally for the day on 25 minutes after Smith had dropped the ball.The game lost some of its early tempo but Bryan Prunty, who earlier hit the bar, sealed Airdrie's progression with a 70th-minute free-kick.