Both sets of fans belted out 'You'll Never Walk Alone' before kick-off, but Celtic quickly looked isolated. Emre Can opened the scoring from the penalty spot inside the first 10 minutes, and although Daizen Maeda then met an Arne Engels cross to restore parity, the Adeyemi show soon followed. The Germany forward - who missed the Euros on home soil this summer - first latched onto a Julian Brandt through-ball before converting, then arrowed a rasping effort in from a tight angle. There was still time for another penalty - this time converted by Serhou Guirassy - before Adeyemi completed a first-half hat-trick with a cool finish beyond Kasper Schemichel.
Celtic made a couple of changes at the break, Brendan Rodgers no doubt hoping the fresh legs could help turn the tide, but Dortmund's charge continued unabated, even after injury had forced Adeyemi off. Nico Schlotterbeck slipped the ball to Guirassy past the hour mark and the former Stuttgart man still had plenty to do, but he danced past his markers before finishing well. Felix Nmecha, another second-half substitute, then added gloss to the scoreline with a thumping finish into the bottom corner and it ended 7-1 at the Signal Iduna Park - Dortmund's record European victory.
Match stats
Adeyemi is the youngest German to reach 10 Champions League goals, three months inside his 23rd birthday.
He is also just the second German to score a first-half hat-trick in the Champions League after Mario Gómez for Bayern Munich against Napoli in November 2011.
As a player, Şahin made 24 Champions League appearances in the colours of Dortmund (20) and Real Madrid (four).
Dortmund have played in three Champions League finals, winning the competition in Munich in 1996/97.
BVB have now won four of five meetings with Celtic to date, and seven of 17 against Scottish clubs (D5, L5).
Engels, 21, made 53 appearances for Augsburg and became the youngest Celtic player to score and assist on his Champions League debut on Matchday 1.
Adeyemi went off as an injury concern but the next flurry is about managing minutes. Couto, Brandt and Groß make way, replaced by Bensebaini, Beier and Nmecha.
57'
Kühn comes close
Nicolas Kühn has Celtic's best chance for a long time at the other end, but Kobel is equal to it.
55'
Duranville effort
UCL debutant Duranville is the next to test Schmeichel. The Dane saves this time, and not for the first time!
54'
Ryerson now
Julian Ryerson is the next to try his luck, but he's denied by Schmeichel before committing a foul on Hatate.
48'
Adeyemi off
If ever anyone deserved a standing ovation. Adeyemi makes way for Julian Duranville after scoring his eighth, ninth and 10th Champions League goals.
46'
Back underway
Dortmund lead Celtic thanks, in large part, to an Adeyemi hat-trick. What a frenetic first half! What will the second bring?
Kick-off!
46'
Celtic subs
The visitors have made a pair of changes, with Reo Hatate and Alex Valle replacing Paulo Bernardo and Greg Taylor.
Half-time
44'
Late flurry
Waldemar Anton and Greg Taylor exchange shots at either end.
42'
Adeyemi's on fire!
Adeyemi completes his hat-trick with a cool finish past Schmeichel! 5-1 Dortmund.
Kasper Schmeichel brings Jamie Gittens down in the box, and is booked. Can BVB take advantage?
3'
Engels' angles
Former Augsburg man Arne Engels takes a corner but it comes to nothing.
1'
Kick-off!
We're underway at the Signal Iduna Park, with the Yellow Wall in full voice. Both sets of fans belted out You'll Never Walk Alone in unison.
Kick-off!
More on Dortmund's team
Another American, Gio Reyna, is Dortmund's only injury absentee. Serhou Guirassy looks to have made the No.9 spot his own, meanwhile, ahead of fellow summer arrival Maximilian Beier. Marcel Sabitzer and Niklas Süle are among the first-team regulars who will have to content themselves with a place on the bench.
More on Celtic's team
USMNT centre-back and defensive stalwart Cameron Carter-Vickers is out with a toe injury. Compatriot Auston Trusty replaces him at the back. Record signing Arne Engels, who recently arrived from Augsburg, starts in a three-man midfield, with another former Bundesliga man, Nicolas Kühn, up ahead.
He scored his first Champions League goal for Dortmund against Club Brugge - here are all of his Bundesliga strikes for you to feast your eyes on.
Familiar faces
Arne Engels, the Belgian who spent the past two seasons with Augsburg is likely to feature, but most eyes will be on Nicolas-Gerrit Kühn. The German striker from Hannover spent time in Bayern Munich's academy, and is now starring for Celtic with five goals in nine games.
Both sides have a relatively clean bill of health with Giovanni Reyna the only certainty to miss out. Jamie Gittens and Marcel Sabitzer are dealing with knocks but could well return, and the same can be said for Celtic's Cameron Carter-Vickers.
Şahin on playing under Rodgers at Liverpool
"We were together for a short time. He is a coach who originally comes from Northern Ireland, but has a Spanish touch and an idea of football that goes beyond possession. I found his training sessions, his idea of football, very, very interesting. Tomorrow we will see each other again after twelve years, and I am looking forward to the duel."
"They were very dominant in their first Champions League appearance. It is a prestigious club with great talent at the club, a fantastic coach. It will be a challenge for us, but of course it will also be a big challenge for them, one they have not had so far this season. I am looking forward to it. It would not be fair to call them underdogs."
"I'm always someone who says: we defend together and we attack together. That's why I see Greg (Kobel) as our first offensive player and Serhou (Guirassy) as our first defender. Everyone on both sides has to take responsibility. I'm trying to do my part."
Groß on his first Champions League match
"This is very, very special for me. Even the Bundesliga evening games were unbelievable for me. We won them all, the fans carried us at times. I always look forward to the home games the most, and the Champions League at home will be a huge highlight for me. I can hardly wait."
Celtic currently top the Scottish Premiership on goal difference ahead of Aberdeen with six wins from six. The Hoops are back under the stewardship of Brendan Rodgers who added his third league title and Scottish Cup in his second stint last season.
Dortmund's latest English talent scored twice last time out in Europe to down Club Brugge and has been flying this season. Celtic will have to be very wary of the tricky winger.
History on BVB's side
Despite being two of the biggest teams in their respective countries, Dortmund and Celtic have never faced off in the Champions League before. However, they do have some history. The pair have faced off twice in the UEFA Cup with BVB progressing on both occasions, winning three out of the four matches.
Watch: Borussia Dortmund chasing another European dream
Can BVB go one better than last season's run to the UEFA Champions League final?
2:03
Watch: Borussia Dortmund 4-2 Bochum - highlights
Dortmund enter this clash on a high after four unanswered goals against Bochum last time out. BVB overcame an early scare to confidently win at home.
0:14
Watch: Can: "Fans always behind us"
Dortmund's captain praised the fans and the Yellow Wall for backing the team as they came form 2-0 down to beat Bochum on Friday.
Welcome!
Thanks for joining us for build-up and live coverage of Borussia Dortmund's second UEFA Champions League game of the 2024/25 league phase at home to Scottish champions Celtic on Tuesday.
