The Japanese international hadn't scored in competitive action since May 2013 following two seasons at Premier League side Manchester United FC, but slotted back in seamlessly for a BVB side aided and abetted on the day by further strikes from Adrian Ramos and Pierre-Emerick Aubameyang. Freiburg's first goal of the season was merely academic.
Die Breisgauer made the trip without a win on Dortmund soil in eight attempts, but they started brightly enough as Admir Mehmedi warmed the palms of Roman Weidenfeller inside 30 seconds. BVB needed no invitation to respond, with Kagawa firing wide on the turn and Kevin Großkreutz going through on goal only to be denied by the onrushing Roman Bürki.
Kagawa was running the show from midfield and the 25-year-old playmaker might have been celebrating his first Bundesliga goal in over 850 days were it not for Marc-Oliver Kempf's last-ditch efforts to hook Großkreutz's deft cut-back behind for a corner. Dortmund continued to ask all the questions as the half wore on, but Freiburg were getting enough men behind the ball to keep the hosts at bay.
Kagawa on cue
That said, the visitors soon buckled under the pressure as Großkreutz collected Kagawa's defence-splitting pass to tee up Ramos for his second league goal in as many games. A similarly incisive breakaway did for Freiburg in the 40th minute, with Ramos the provider this time for Kagawa to sweep into the bottom corner and send the Signal Iduna Park into raptures.
Dortmund were comfortable and could have been forgiven for taking their foot off the gas after the restart. Jürgen Klopp nevertheless patrolled the touchline with trademark integrity in an effort to squeeze the very last sinew from his supreme disciples, with Henrikh Mkhitrayan heeding the call on the hour-mark, collecting a Ramos back-heel and spooning onto the roof of the net.
Aubameyang ices the cake
Cramp appeared to get the better of Kagawa in the 65th minute, the departing Japanese star rightly earning a standing ovation for his lung-busting efforts on his first Bundesliga appearance since the 4-0 win over Freiburg back on 5 May 2012 in Dortmund's double-winning campaign.
Ciro Immobile duly entered the fray, but it was fellow substitute Aubameyang who prompted one last round of delirious celebrations in the stands. Christian Günter missed his kick in midfield, allowing Dortmund's resident speed demon to race clear and cap a fine team display with a delightful chip, before Oliver Sorg squeezed in a 90th-minute consolation for the visitors.
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