Kieffer Moore put the Reds ahead after just 15 seconds then Cauley Woodrow made it 2-0 on the stroke of half-time. Woodrow got another midway through the second half before the hosts pulled one back then Jacob Brown completed the rout.
Leaders Luton Town also won so remain six points clear but draws for Portsmouth and Sunderland mean Barnsley are three points clear in second.
The negative for the Reds was that Moore had to be carried off on a stretcher following a sickening clash of heads with Gabriel Zakuani which saw him spend eight minutes on the ground. He was knocked out and went to hospital.
Head coach Daniel Stendel kept the exact same squad as for the win over Scunthorpe United in their last game a week previously. The visitors were the better side in the first half, constantly threatening to get in behind the weak home defence. Barnsley could easily have been four goals up after 20 minutes then, after Gillingham had two good chances and a period of pressure, the Reds finished the half well.
The first move of the game saw Jacob Brown outmuscle Connor Ogilvie on the right touchline then send in a low cross which Mamadou Thiam dummied so it reached Cameron McGeehan inside the box. The shot was saved by Tomas Holy but Moore blasted in the rebound from five yards out for his 18th of the season.
Moore almost netted another on five minutes as he robbed Gabriel Zakuani then went clean through on goal but Holy got down to his right to make a very good one-on-one save. Moore should have passed to Thiam who was free on his left.
Alex Mowatt then missed two superb chances within a minute as he was denied one-on-one by the impressive Holy after being put through by Thiam then smashed against the crossbar from close range when Brown headed down Thiam’s left-wing cross.
The Gills then had two excellent chances to level. Adam Davies dropped the ball after crashing into team-mate Ethan Pinnock from a free-kick but Brandon Hanlon volleyed over from close range. Seconds later, Tom Eaves went clean through on but Davies did well to deny him while diving down to his right.
The match then settled down after a frantic first 20 minutes, with Gillingham having more of the ball but struggling to break down Barnsley who constantly looked to break on the counter-attack. Home player Billy King lost the ball to Thiam just before the break but he shot straight at Holy under pressure from 15 yards out.
It was 2-0 in the 45th minute when Woodrow met Thiam’s good left-wing cross at the back post and headed it beautifully over Holy and into the net.
The early part of the second half saw Barnsley even more content to sit back and soak up pressure then hit their hosts on the counter-attack. Brown headed over from a Pinillos cross then the Gills survived an astonishing scramble which saw Holy deny Thiam twice before McGeehan’s shot was deflected over by a defender.
Mowatt’s 30-yard shot was turned over by Holy and the Reds scored their third from the resulting left-wing Thiam corner which was flicked on by Liam Lindsay for Woodrow to force in from close range at the far post. It was his 11th of the season.
The Gills pulled one back with ten minutes left when a left-wing free-kick was cleared to the edge of the box where substitute Elliott List fired into the bottom right corner.
In the last of 12 added minutes due to Moore's injury, Brown made it 4-1 with an eight-yard shot which hit the underside of the bar before bouncing into the roof of the net, after good work by Thiam and Bahre.
Barnsley (4-4-2): Davies; Cavare, Pinnock, Lindsay, Pinillos; Brown, McGeehan, Mowatt (Dougall 80mins), Thiam; Moore (Green 90), Woodrow (Bahre 71). Unused: Walton, Fryers, Hedges, Adeboyejo. Yellow cards: Cavare. Goals: Moore 1, Woodrow 45, 71, Brown 90+12. Gillingham: Holy; Fuller, Zakuani, Ehmer, Ogilvie (Charles-Cook 79mins); Byrne, Rees (Parrett 65); Hanlon, Burke, King (List 54); Eaves. Unused: Hadler, O’Neill, Lopes, Reilly. Goal: List 81.
-
13:37pm
-
-
15:03pmGOAL!
-
15:05pm
-
15:06pm
-
15:07pm
-
15:08pm
-
15:08pm
-
15:11pm
-
15:13pm
-
15:15pm
-
15:15pm
-
15:17pm
-
15:20pm
-
15:20pm
-
15:21pm
-
15:23pm
-
15:24pm
-
15:24pm
-
15:26pm
-
15:30pm
-
15:33pm
-
15:34pm
-
15:34pm
-
15:36pm
-
15:37pm
-
15:40pm
-
15:44pm
-
15:45pm
-
15:47pmGOAL!
-
15:48pm
-
15:49pm
-
15:54pm
-
15:54pm
-
16:06pm
-
16:08pm
-
16:12pm
-
16:13pm
-
16:15pm
-
16:17pm
-
16:21pm
-
16:22pm
-
16:25pm
-
16:29pm
-
16:31pm
-
16:31pm
-
16:31pmGOAL!
-
16:33pm
-
16:35pm
-
16:37pm
-
16:39pm
-
16:40pm
-
16:41pmYELLOW CARD
-
16:42pmGOAL!
-
16:43pm
-
16:44pm
-
16:45pm
-
16:46pm
-
16:48pm
-
16:50pm
-
16:51pm
-
16:51pm
-
16:55pm
-
16:57pm
-
16:58pm
-
17:00pm
-
17:02pmGOAL!
-
17:03pm
-
17:03pm