Youri Tielemans scored a penalty late in extra time as Belgium produced a sensational comeback from two goals down to defeat Senegal in a dramatic last-32 World Cup tie.
The last-gasp victory helped them book a last-16 meeting with either the United States or Bosnia-Herzegovina.
Rudi Garcia’s men had looked to be heading out as they trailed an impressive Senegal by two goals with only four minutes remaining of normal time.
But half-time substitute Romelu Lukaku flicked in Thomas Meunier’s cross to give them a glimmer of hope.
And they made the most of the unexpected lifeline in the 89th minute as Leandro Trossard’s cross into the box was missed by goalkeeper Mory Diaw and skipper Tielemans headed in to level at 2-2 and force extra time.
The Belgian pair were earlier seen having a heated argument before the second-half hydration break, with Lukaku stepping in to separate them.
Their comeback stunned Senegal after goals from Habib Diarra and Ismaila Sarr had given them a deserved 2-0 lead.
And having rescued themselves in normal time, Belgium snatched a controversial winner in the 125th minute.
After Dodi Lukebakio’s shot brushed the crossbar, they were awarded a penalty for Lamine Camara’s sliding challenge on Tielemans just before that chance following a video assistant referee (VAR) review that took seven minutes.
Up stepped Aston Villa midfielder Tielemans to calmly slot the spot-kick into the top corner and settle the outcome.
Analysis: Belgium keep dream alive as Senegal suffer more heartbreak
Belgium’s golden generation has slowly waved their goodbyes, leaving behind a sense of unfulfilled potential.
But it was striker Lukaku, one the final remnants of a talented team that failed to succeed on the biggest stage, who inspired their unlikely comeback.
The 33-year-old had played just 69 minutes for Napoli last season because of injury, with manager Garcia saying he was “out of shape” when naming him in his World Cup squad.
Yet the former Chelsea and Inter Milan forward again displayed his poaching instincts before the Tielemans double.
It meant Lukaku and Kevin de Bruyne, withdrawn here after 56 minutes to his visible frustration, have another shot at the glory that has eluded them for their country.
For Senegal, however, it was further heartbreak on the international stage.
They defeated Morocco 1-0 in the Africa Cup of Nations final in January but were later stripped of the title after a controversial walk-off in the game following a disputed stoppage-time penalty.
Senegal hoped a deep run in this World Cup could offer some redemption and their threat in Seattle was obvious after only 13 minutes as Crystal Palace forward Sarr struck the the post and was unable to turn in the rebound.
From a Sadio Mane delivery, Sarr then crashed a header against the same upright 12 minutes later, but this time Sunderland’s Diarra was there to steer home from close range.
Pape Thiaw’s side pulled further ahead six minutes after the restart with a brilliant goal.
Centre-back Moussa Niakhate’s long ball caught the Belgium defence napping and Sarr burst through, taking the ball on his chest before smashing a stunning effort past Thibaut Courtois.
Senegal keeper Diaw was barely troubled for much of the game, but was beaten by Lukaku’s clever finish in the 86th minute.
Tielemans then stepped up to deliver the decisive blows to deepen the pain of the African side – and breathe new life into Belgium’s campaign.
