Jurgen Klopp's men secured top spot in UEFA Champions League Group D by drawing 1-1 with Anderlecht at Signal Iduna Park on Tuesday, with Immobile socring a 58th-minute opener.
Dortmund's success in Europe's elite competition has been a stark contrast to their poor domestic form, though, and they sit just a point above the relegation zone in 14th.
A 1-0 over Hoffenheim last Friday lifted Dortmund off bottom spot and Immobile is seeking nine points from matches against Hertha Berlin, Wolfsburg and Werder Bremen before Germany's top flight takes its annual break.
"I want us to win the three remaining games this year in the Bundesliga so we can go into the Christmas break more relaxed," he told Dortmund's official website.
Immobile's goal was just his sixth since joining from Torino in the last transfer window and his first since he scored in the 4-1 Champions League win over Galatasaray on November 4.
And the Italian was happy to be back among the goals.
"I hadn't played much in the last few weeks and was looking forward to play again," he added.
"The goal was good for me, and for the team, and the 1-1 draw helped us to win the group."
