Guardiola's side prevailed thanks to Robert Lewandowski's first-half header, the Poland international returning to haunt his former club on his first league visit back to Signal Iduna Park.
Dortmund had the majority of the possession in the second half, but were unable to find an equaliser as Dante, Jerome Boateng and Medhi Benatia kept the door firmly shut.
"I can only congratulate my team, especially Dante," Guardiola said of the defender, who was making only his third league start in the last two months.
"To him I would like to dedicate the win today. He is an incredibly important player for us. I'd like 1,000 Dantes in my team.
"In the first half it was incredibly difficult, in the second we defended very well, but did not play well.
"I would actually like to have played differently today than we played. But I also have to pay attention to who is available.
"I would have liked to have more physical strength in midfield. It's not easy to win in Dortmund. They have great quality.
"We have managed an important step, we have to win four times in order to be champions."
Philipp Lahm made his first start since November after fracturing an ankle, and was replaced with 20 minutes to go by Thiago Alcantara, making his first appearance for a year following a serious knee injury.
"In the end it was tight," Lahm said. Dortmund have an outstanding team. We defended well, we had far too little possession.
"It was a hard-earned victory. For years, Dortmund were our fiercest competitor and it is something special to win in Dortmund."
