The German side top Champions League Group B after the 2-2 draw in Gelsenkirchen, but that outcome looked an unlikely one when Theo Walcott and Olivier Giroud fired the Gunners into a commanding lead after just 26 minutes.
But Klaas-Jan Huntelaar responded on the cusp of half-time and the draw was achieved when Jefferson Farfan's shot went in via Thomas Vermaelen.
Midfielder Holtby, who has been linked with Arsenal, was delighted with the comeback.
He told UEFA.com: "At the end, we were a little bit relieved, but if you look at the whole 90 minutes, and especially the first 20 minutes, I think we had an astonishing game.
"We were 2-0 down, and got back to 2-2. Klaas-Jan Huntelaar had a chance in the second half, but I think 2-2 is alright. We showed our character to come back from 2-0 down, which was great.
"Our team spirit is high, and we knew that if we got a goal before half-time, we had a chance. It was a really good goal by Klaas. We showed that we weren't down, and that we could turn things round.
"We always believe, we have quality players on the pitch who can score a goal at any time."
Roman Neustadter, Holtby's midfield colleague, felt the hosts may have deserved even more from the match.
"It's a real shame that we weren't rewarded for our performance," he added.
"We dictated the game, and had Arsenal with their backs to the wall at the end. We were unlucky with both of their goals.
"But we are still in a very good position to get out of the group, and I'm convinced that we will reach the knockout stages."