The home side started the game on the front foot and were rewarded with the opener after 11 minutes. Marcel Schäfer did well to surge past Tony Jantschke and cross for Knoche whose presence caused the Gladbach defence problems and the ball eventually fell to him to stab the ball home.
The visitors responded and a Max Kruse corner was diverted goal-bound by Roel Brouwers but Diego Benaglio was equal to it.
VfL had two half-chances in quick succession as Naldo saw a header blocked and Vieirinha fired straight at Sommer from 25 yards out.
The Foals must have thought they had equalised when an unmarked Patrick Hermann headed towards goal from close range, only for the Swiss keeper to pull off an outstanding side to preserve his side’s lead.
After the break, Sommer saved well twice from Iva Olic, much to the Croatian’s frustration. Christoph Kramer then went down in the box, pleading a penalty, but referee Wolfgang Stark rightfully ignored the appeal. Kevin De Bruyne then had a long-range effort deflected wide by Alvaro Dominquez.
Lucien Favre replaced Andre Hahn and Max Kruse with fellow wingers Ibrahima Traore and loanee Thorgan Hazard to add impetus to the attack and the two combined straight away only for Benaglio to beat Hazard to the ball.
Late on, Belgium De Bruyne fed in substitute Aaron Hunt but the angle was tight and it ended up being a comfortable save for former Basle man Sommer. The defending got desperate in stoppage time as the Foals pushed for an equaliser but the hosts held on for a huge narrow win.