MORECAMBE suffered a second successive defeat with two early goals firing league leaders Plymouth to the three points.
The Shrimps got off to a shocking start and were two goals down after 11 minutes.
Graham Carey fired the home side into the lead after just 65 seconds. The Plymouth midfielder received the ball just outside the Morecambe box and curled a superb left foot effort into the bottom right hand corner of the Morecambe goal.
The Shrimps hit back with Shaun Miller testing Luke McCormick with a shot on target from the edge of the area before the home side added a second with another fine goal.
Jake Jervis crossed to the far post for Craig Tanner who cut inside and found the bottom corner of the Morecambe goal with a superb curling effort that found the corner of Roche's goal.
From there Morecambe played some neat football throughout the half and created several chances of their own.
McCormick did well to hold on to Kevin Ellison's cross come shot before Tom Barkhuizen volleyed wide and Aaron Wildig saw a shot deflected over the bar by a Plymouth defender.
Miller tested McCormick again from the edge of the area before the home side went close to a third when Peter Hartley fired into the side netting from an acute angle after the Shrimps failed to clear a corner.
The second half saw the Shrimps struggle to turn possession into chances with their best chance falling to substitute Paul Mullin in the 69th minute but he failed to find the target from six yards out after a neat turn.
The home side continued to create the better chances with Roche saving superbly from Carey's right foot shot before the home side went close to adding to their lead on several occasions.
The ever dangerous Carey clipped an effort inches wide and Ryan Brunt's flick was just off target with Roche beaten but in the end it was the two early goals that proved the difference between the sides.
PLYMOUTH: McCormick, Mellor, McHugh, Nelson, Hartley, Sawyer (rep Purrington 88), Tanner (rep Threlkeld 80), Hartley, Carey, Boateng (rep Simpson 54), Jervis, Brunt. Subs not used: Bittner, Cox, Rooney, Harvey.
MORECAMBE: Roche, Beeley, Parrish, Edwards, McGowan, Goodall (rep Molyneux 75), Wildig, Barkhuizen, Devitt (rep Fleming 65), Ellison, Miller (rep Mullin 65). Subs not used: Thompson, Kelleher, Kenyon, Wilson.
Ref: M Bull