A dissapointing performance by the Swans which allowed their lowly Dorset hosts to take all three points at a windswept Hardings Lane.
The game was only ten minutes old when Gillingham took the lead, a free kick from the half way line was helped on by the strong wind and the Swans defence found the ball difficult to clear, William Pike took full advantage by firing in a low shot from 15 yards out which left Dave Evans in the Swans goal no chance.
Just five minutes later the Swans were nearly level, Paul Fahy was felled on the edge of the box and Adam Mace saw his fierce free kick rebound back from the crossbar, Fahy blasting the rebound high over.
On 23 minutes the hosts should have increased their lead but Steven Smith saw his goal bound header cleared off the line by Leroy Odiero.
The Hard, bumpy surface was adding to the problems of the strong wind as neither side could really string a series of passes together and goalmouth action was at a minimum.
On the Half hour a good through ball from Jamie Martin set Fahy clear but his strong run was halted by a last ditch tackle from Nicholas Hewlett.
Just before the interval Richard Thwaite was dispossessed some 25 yards from goal and as the Gillingham forward bore down on goal, Thwaite chased him back and brought the striker down on the edge of the box which earned the Central Defender a caution from Referee Rob Cockle who also added Adam Mace in his notebook for talking out of turn.
The second half started well for Gillingham and a strong run from the dangerous number 10 saw his excellent cross evade everyone in the Swans box.
A thunderous volley by the home sides Daniel Cox was well held by Evans as Gillingham started to up the tempo.
And it was Cox who missed a glorious chance to increase their lead when a cross from the left found him free on the far post but Cox somehow managed to head the ball wide of the open goal.
Manager Leon Sterling made three quick substitutions, bringing on Sean Lawson, Ryan Thwaite and Jamie Hammond in an attempt to shake things up and it looked like it might pay dividends as the Swans upped the tempo themselves.
On 73 minutes Sam Turl was grounded after a strong challenge but the ball fell nicely for Callum Brown, as referee Cockle played a good advantage, Brown ran on and let fly with a thunderbolt of a shot from 25 yards which Sam Filikns in the home goal did well to reach, pushing the ball round for a corner.
Slimbridge were going forward in numbers now in an attempt to get an equaliser and forced a series of corners resulting in Hammond and Fahy going close but in the final minute of the match and with Keeper Evans joining the Swans forwards in the box for yet another corner disaster struck when the ball was cleared downfield for the Gills number 10 to run on and fire into an empty net.
Slimbridge must now pick themselves up for what looks like on paper three very difficult final games, starting with Willand Rovers at home on Saturday followed by a Bank Holiday weekend away at both Buckland Athletic on Sat 2 May and Finally Willand on Mon May 4.
Team; EVANS, TURL, BROWN,ODIERO,RICH THWAITE, WARD, TURNER (RYAN THWAITE 67) PARROTT, MARTIN (LAWSON 64) FAHY, MACE (HAMMOND 70).
SUB NOT USED TWYMAN.
MAN OF THE MATCH, CALLUM BROWN.