Inter failed to get beyond the Champions League group stage for a second successive season after losing 2-1 at home to Barcelona, with Ansu Fati's late winner making him the youngest scorer in the competition's history.
The Serie A leaders needed to at least match Borussia Dortmund's result against Slavia Prague due to being level on seven points before the game, but the Germans emerged 2-1 victors to secure their progression as Inter were left to regret their own wasteful finishing.
After weathering an early Inter storm, a much-changed Barca went ahead through fringe forward Carles Perez, though their lead did not last – Romelu Lukaku blasting in from 20 yards.
Lukaku was otherwise wasteful in front of goal, however, missing a particularly fine opportunity early in the second period, before the visitors sealed Inter's fate late on through 17-year-old Fati, dropping the Italians into the Europa League.
A purposeful start from Inter saw Lukaku have a goal disallowed for offside, while the Belgian had a close-range effort crucially deflected over by Clement Lenglet.
Barca steadily gained a foothold, however, and capitalised on Inter's profligacy in the 23rd minute – Perez sweeping home after Diego Godin deflected Antoine Griezmann's incisive pass to the forward.
Lenglet inexplicably missed the target from 12 yards just past the half-hour mark and Inter made him pay on the stroke of half-time, Lukaku drilling home after excellent hold-up play by Lautaro Martinez on the edge of the box.
Lukaku should have got a second just after the hour mark but he lashed straight at Neto in a one-on-one opportunity.
Martinez thought he had grabbed a late victory to take Inter through, yet Lukaku had strayed offside just prior to his fellow striker prodding home.
And substitute Fati fired in a historic winner four minutes from time to destroy Inter's hope of joining them in the last 16, sending a low shot in off the left-hand post.
What does it mean? No second chances for Inter
Antonio Conte attempted to motivate his Inter players by highlighting there were "no second chances" – this was their last opportunity to prove they could translate their Serie A season to the Champions League.
However, they wasted so many clear-cut opportunities. Inter's elimination is by no means down to any Barca brilliance – they did not even have Lionel Messi in the squad. No, they are out because of their own mistakes.
Alena and Todibo impress in Barca's Italian job
It has been a difficult season for Carles Alena, with a lack of first-team football resulting in links with transfers to other clubs. Yet in San Siro he proved he is capable of impressing for Barca, creating a team-high four chances.
Jean-Clair Todibo was arguably the visitors' best player, though, showing fine ability on the ball and immense composure, despite this being only his third outing of the campaign.
Careless Lukaku costs Inter
Although he got the goal to secure parity before half-time, Lukaku was otherwise a massive disappointment.
His lack of composure when smashing at Neto in the second half was startling, while he spurned other chances and was the one who was crucially in an offside position for the late disallowed Martinez goal.
Key Opta facts
- Barcelona have become only the second team to avoid defeat in 20 consecutive Champions League group stage games (W14 D6), after Real Madrid between 2012 and 2017 (30 matches).
- Antonio Conte has failed to progress from the group stages in two of his four Champions League campaigns in his coaching career (also in 2013-14 with Juventus).
- This was Barcelona's first win away at Inter in any European competition since September 1959 (4-2 in an Inter-Cities Fairs Cup quarter-final).
- Peter Oforiquaye was the Champions League's youngest scorer prior to Ansu Fati. The former was 17 years abd 194 days when he found the net against Rosenborg in October 1997.
- Aged 21 years and 297 days, Carles Perez is the youngest Spaniard to score on his Champions League debut for Barcelona since Cristian Tello (20y 209d).
Inter return to Serie A action on Sunday at Fiorentina, as they await to hear their Europa League opponents in Monday's draw. Barcelona, meanwhile, go to fourth-placed Real Sociedad on Saturday, ahead of next week's Clasico.