By FOX Sports Staff
Julian Draxler took just 11 minutes to open the scoring for the home side as he latched onto a cross from the right by Atsuto Uchida.
The Japanese winger sent in another superb delivery a short while later with an unmarked Klaas Jan-Huntelaar the beneficiary as the Dutchman made the easiest of headers to double his side's advantage.
Dortmund retaliated and came up with a goal in the second half as Robert Lewandowski got on the end of a smart through-ball by substitute Marco Reus and made no mistake from nine yards out. But, try as they might, Jurgen Klopp's men simply could not find the leveller and Schalke registered a second successive win over their arch-rivals this season.
"In the first half, we played outstandingly and were able to make one or two more goals from the aggressive duels that we won. We also played very good football," Keller told reporters after the game.
"The first goal was huge for us early on. I am proud of how the team held against the [BVB] pressure and earned plenty of counterattacking opportunities."
The only sour note for the Royal Blues was the injury picked up by star striker Huntelaar and Keller is already fearing the worst.
He added: "Huntelaar's [injury] could be long [term]."
Opposite number Jurgen Klopp felt that Schalke thoroughly deserved the win as they were far more determined to secure a result on the night. But he felt that mistakes committed by his players might have contributed to their downfall as well.
"Congratulations to Schalke for a deserved victory, but for us it still feels unnecessary because we had some very good moments in our game after Schalke had taken the lead," he said.
"In the first half we played too defensively and made some tactical mistakes. We allowed chances which we should not have been allowing.
"Whenever we were determined, we were dangerous, but we did not take our chances. Schalke had a lot more shots on goal.
"A draw would not have been undeserved, but it was not to be. Schalke used their good half to get two goals, but our good phase could only muster one. Therefore, we deserved to lose."
Schalke also announced that captain Benedikt Höwedes had agreed a contract extension and would stay on at the club until 2017.