Chelsea striker Michy Batshuayi and Tottenham defender Jan Vertonghen were among the goalscorers as Belgium secured a thrilling 4-3 win away to Bosnia-Herzegovina in Sarajevo on Saturday.
Belgium came into their World Cup qualifier having already booked their place at next year's finals in Russia - the first European side to do so - with much of the pre-game talk surrounding Vertonghen's record-equalling appearance.
And things seemed to be going smoothly for Vertonghen and his compatriots when Thomas Meunier latched onto Eden Hazard's cross to open the scoring in just the fourth minute.
But the Red Devils were then left stunned when the hosts, who sit second in Group H, turned the game on its head with two goals in nine minutes through Haris Medunjanin and Edin Visca as Fellaini was forced off in the 29th minute with a knee injury - a week before Manchester United play Liverpool at Anfield.
Roberto Martinez's battled back and were rewarded when Batshuayi poked in from three yards out after his former Chelsea teammate Asmir Begovic had spilled Yannick Carrasco's shot back out into the area.
Vertonghen then scored on his record-equalling night to make it 3-2 to Belgium, although Bosnia levelled through Dario Dumic with eight minutes to play.
Despite having already qualified, Belgium looked for the winner and got it just a minute later when Carrasco slotted in Meunier's pass to seal a 4-3 victory for Martinez's side ahead of their home match with Cyprus on Tuesday.
