It took an own goal, the tournament's ninth, with just five minutes remaining in Duesseldorf to give France a nerve-jangling victory that raised fresh questions about the form of their key forwards.
While France celebrated Jan Vertonghen's own goal with gusto, boss Didier Deschamps acknowledged it could have been a far more comfortable passage to the last eight if they taken a host of earlier chances.
No France player has scored in open play in four matches in Germany as the likes of Kylian Mbappe and Antoine Griezmann struggle to reproduce the thrilling performances which carried Les Bleus to the 2022 World Cup final.
Deschamps's side have been worryingly inaccurate in front of goal and they needed two fine saves from Mike Maignan to keep them on level terms before Vertonghen diverted Randal Kolo Muani's shot into his own net.
France had the better of possession, played and completed more passes and had 20 shots to Belgium's five but only worked Red Devils goalkeeper Koen Casteels once before Vertonghen's own goal.
Casteels did well to push away Aurelien Tchouameni's deflected effort from distance three minutes after the half-time but France spurned a host of other presentable opportunities.
Tchouameni smashed over a great chance after a mesmerising raid from Mbappe just before the break and Marcus Thuram should have hit the target when he headed wide from Jules Kounde's pinpoint cross.
"We wasted a few chances out there, maybe six or seven, let's hope it doesn't become a psychological problem with the team, but we'll work on it," Deschamps told reporters.
Mbappe won the Golden Boot at the last World Cup in Qatar, but the Real Madrid star has only a penalty -- scored against an already eliminated Poland team -- to his name at this year's Euros.
Goal-shy France
That goal is the only one to be scored by a France player at the tournament as both of their wins have been secured by own goals.
Mbappe's overall play was lively on Monday but his finishing was unusually erratic.
The way he snatched at an excellent opportunity in the 56th minute led Deschamps to suggest that the mask he is forced to wear after breaking his nose is affecting his vision.
"He's getting more and more used to it. It's sweaty and that sweat can get into his eyes. I've not tried on the mask so I don't know, but yes it could have an impact on his vision," said Deschamps.
"Everything that is in front of him is ok, but maybe the peripheral vision is a little bit off."
Also lacking threat was Griezmann, who looked isolated on the right wing of a four-man midfield, a position he rarely plays for France and from where he failed to deliver his usual deftness and creativity.
Both Deschamps and right-back Jules Kounde praised Griezmann for his defensive work, but he posed little danger beyond one early scuffed effort from distance.
"It was just a question of balance, as I said before the game, there was always the possibility we might have one or two players not in their best position," said Deschamps.
"It is a position he plays in regularly for his club too. He was very good on the ball even if he can be more clinical.
"He is intelligent, and when there are big matches I know I can count on him."
France will play either Portugal or Slovenia in the last eight in Hamburg on Friday.
