FIRST-half goals from Nicky Maynard and Martyn Waghorn moved Latics up to seventh place in the Championship after a comfortable evening’s work.
But the night was completely overshadowed by a serious-looking injury sustained by Ben Watson, which could well have ended his season.
Latics barely got out of second gear - they didn’t have to - as they recorded the two-goal victory required to leapfrog Ipswich and Brighton in the standings.
After roaring out of the blocks and putting the Tykes on the back foot, Latics finally took the lead 10 minutes before the break when Jean Beausejour teed up Maynard for his third goal in his last two games.
And the points were virtually secured a minute before the interval when the impressive James McClean crossed for Waghorn to nod home his first goal for the club from close range.
The second half was merely a procession as Latics sat back and defended their lead, with the visitors lacking the quality to make a game of it or even force Ali Al Habsi into a save worthy of the name.
But all thoughts were elsewhere long before the final whistle, after Watson came off second best following a sickening collision with Barnsley defender Martin Woods.
The exact extent of the damage remains to be seen, but the sight of Watson receiving oxygen as he left the pitch - and his subsequent departure in an ambulance - left everyone fearing the worst.
The ironic thing is that Watson had been all-but ruled out of the game by Uwe Rosler, after limping out of Saturday’s FA Cup victory at Cardiff.
But he was passed fit to take his place in a starting XI containing five changes, with Maynard, Waghorn, Leon Barnett, James McArthur and McClean restored to the side.
Maynard, McArthur and Waghorn were immediately involved as Latics flew out of the blocks in search of an opener.
At the other end, Tom Kennedy’s cross was headed inches over the top by Nick Proschwitz, which gave Latics a real scare.
But that was a rare moment of alarm as Latics gained a real stranglehold on the game.
McClean was seeing plenty of ball down the left and absolutely terrorising opposite number Ryan McLaughlin.
There was then a lengthy stoppage as Watson and Woods collided on the edge of the Wigan box, with the FA Cup final hero coming off a clear second best.
Josh McEachran was Watson’s replacement in the engine room, although there was understandably a more sober atmosphere in the stadium from then on.
Latics were almost given a gift when an under-hit backpass from Dale Jennings found only Maynard, with Luke Steele racing off his line to collect.
Maynard then won himself a yard before firing weakly at Steele, with Chris McCann firing over after great work from McClean.
Latics were getting closer and closer to an opening goal, with a delightful ball from McEachran dissecting the defence and playing in Beausejour.
However, the Chilean opted to cross instead of shooting, and Tom Kennedy was able to clear before Waghorn could get there.
The goal was undoubtedly coming, though, and the home side finally broke the deadlock on 35 minutes.
Again Beausejour was involved, but this time his decision-making was spot on as he waited for the perfect moment to lay it on a plate for Maynard, who couldn’t miss.
And goal number two wasn’t long in coming, McClean skinning McLaughlin down the flank and crossing for Waghorn to head home.
Al Habsi was at least forced into action before the break, although Jim O’Brien’s effort from the edge of the area barely made it into the goalkeeper’s arms.
The Tykes made two changes at the break, but Latics continued to keep them at arm’s length with relative ease.
Woods fired a bouncing ball over the top, while Emmanuel Frimpong’s free-kick deflected on to the roof of the net.
A dangerous-looking cross was flicked away by Emmerson Boyce as the Tykes supporters behind the goal sensed their time had come.
That was the cue for Latics to make their final two changes, Roger Espinoza and Marc-Antoine Fortune coming on for Maynard and, surprisingly, McEachran.
Barnsley continued to push and Jennings headed just wide of the mark with Al Habsi looking on anxiously.
Latics then created and squandered an opportunity to kill the game completely, when Waghorn’s free-kick was headed on by Boyce for Fortune to miskick wide.
Substitute Brek Shea beat two defenders with quick feet before firing high and wide, before Fortune passed up another chance right at the death by shooting against the legs of the goalkeeper.
Latics: Al Habsi; Perch, Boyce, Barnett, Beausejour; McArthur, Watson, McCann; Waghorn, McClean, Maynard.
Subs: Nicholls, Crainey, Kiernan, McEachran (for Watson, 20), Gomez, Espinoza (for McEachran, 75), Fortune (for Maynard, 75).
Barnsley: Steele; McLaughlin, Ramage, Cranie, Kennedy; O’Brien, Frimpong, Woods, Jennings; O’Grady, Proschwitz.
Subs: Turner, Nyatanga (for McLaughlin, 46), Dawson, Lawrence, Cywka, Shea (for O’Grady, 46), McCourt (for Woods, 64).
Star Man: James McClean