The result gave City a 4-2 win on aggregate to set up a Champions League semi-final clash with Paris Saint Germain.
Dortmund’s dreams of the last four in Europe are over, but, more worryingly, they are seven points from qualifying for next season’s Champions League with six Bundesliga games left.
However, their young squad is maturing and 17-year-old Bellingham’s outstanding performance grabbed Pep Guardiola’s attention.
Four days after scoring his first Bundesliga goal, the England midfielder opened the scoring against City to become the second youngest goal-scorer in the knock-out stages of the Champions League.
“I can’t believe he is only 17,” said City manager Guardiola.
“Maybe he is a liar,” joked the Spaniard. “He is so good, a fantastic player.”
“I’ve seen him shouting to the centre-backs, demanding the ball. At that age, it’s incredible.”
Bellingham is by no means Dortmund’s only teen talent.
Striker Ansgar Knauff, 19, capped a week to remember by starting both legs against City after scoring his first Bundesliga goal last Saturday.
Giovanni Reyna, Knauff’s second-half replacement against City, is a full USA international at 18.
Dortmund striker Youssoufa Moukoko, currently sidelined by injury, is only 16, but last December he became the youngest player in Champions League history.
Moenchengladbach boss Marco Rose will replace Edin Terzic as Dortmund’s head coach next season, but it remains to be seen which young stars will remain.
Without Champions League football and facing a deficit of around 75 million euros ($90 million) in lost income due to the Covid-19 pandemic, Dortmund face a fight to keep the squad intact.
Manchester United are reportedly still interested in England winger Jadon Sancho, 21, while the likes of City, Real Madrid and Barcelona are reportedly courting 20-year-old Haaland who has banged in 33 goals this season.
Haaland has not scored in his last seven games for club or country, but still creates goals and was involved in the build-up for Bellingham’s opener on Wednesday.
Terzic says the off-field speculation about his future has had little impact on Haaland.
“It doesn’t do that much to him. We see him shooting in training and continuing to work hard,” said Terzic.
“We don’t measure him only by the goals he scores for us, it’s more important that he works well for the team.”
However, Haaland has made it no secret that he wants to play Champions League football next season.
His contract expires in 2024 and a reported exit clause — for 75 million euros — only becomes active in 2022.
Dortmund sports director Michael Zorc has made it clear selling Haaland this summer is not an option.
While Haaland’s agent Mino Raiola is speaking to the likes of Real and Barcelona, Zorc acknowledged there is “a completely normal conflict of interest”.
Raiola has moved to play down any tension “there is no war between us and BVB (Dortmund)”, but the club has said the player cannot leave “without a signature from BVB”.
Zorc has been here before.
He managed to keep Robert Lewandowski, who was at the time being courted by several top clubs, at Dortmund until the Poland striker left for Bayern Munich in 2014 after his contract expired.