For the hosts, André Schubert opted for three alterations from the side that beat FC Ingolstadt 04 at the weekend. Tony Jantschke, Fabian Johnson and André Hahn were dropped as Ibrahima Traoré, Thorgan Hazard and Raffael earned a place in the starting side.
Luis Enrique made five changes to the starting eleven which confidently dispatched Sporting Gijon by five goals to nil. Jeremy Mathieu, Lucas Digne, Andre Gomes, Rafinha and Arda Turan found themselves out of the team, opening up space for Javier Mascherano, Jordi Alba, Ivan Rakitic, Andres Iniesta and Paco Alcacer.
Hazard has Gladbach ahead at the break
Gladbach were happy to play the Barca way - for lack of a better term - in the first half and eventually matched them stride for stride. Neymar had the first meaningful effort of the match but Yann Sommer dealt with it easily, though the build-up play was trademark Barcelona. Moments later, Luis Suarez shot wide from a Nico Elvedi mistake.
As the game got to the 20th minute, things began to even out. Julian Korb made a fantastic intervention and Rakitic was denied by Sommer, but Traoré issued a warning to Barcelona that the Foals were very much in the game and could cause problems when the chance arose.
That was just the case in the 34th minute as Gladbach broke away with real pace. Raffael led the counter charge and slipped Mo Dahoud into the box with a brilliantly timed pass. The young German was aware of his surroundings and picked out Hazard in the mid-table to finish past Marc-André ter Stegen.
Barca responded before the break as a raking ball from Rakitic was set up perfectly for Suarez to volley, although Sommer's save and Andreas Christensen's clearance kept the home side ahead at the break.
Turan and Pique see Barca to second win
The Foals were dealt a big blow at the start of the half as Raffael was forced off with injury, with Fabian Johnson his replacement. That proved to be a turning point as Gladbach seemed to be pushed into their shells. Johnson ran well and got some useful rest for his side, yet it just wasn't sticking as it did with Raffael.
Shots began to test Sommer, with Rakitic's long-range effort stinging his hands before the breakthrough was made. Some wonderful play down the right eventually saw the ball worked inside to Neymar, who produced a superb pass over the Gladbach defence. Arda Turan was on hand to smash a half volley past the helpless Sommer from close range.
Things went from bad to worse less than 10 minutes later as Barca grabbed their second. Neymar was again the architect as his corner went to the edge of the box and was truck goalward by Suarez. His effort was spilled by Sommer and Pique was on hand to scramble the ball over the line and hand the visitors the lead for the first time.
The Swiss stopper did recover to make a good save from a Turan chip, though that was the final major chance of the game as Enrique's side were happy to keep the ball for the remainder of the game. Gladbach are now bottom of the group after Celtic and Manchester City drew 3-3, allowing Barcelona to go two points clear at the top.