The Azzurri had only lost two of their 20 matches in the league phase of this competition heading into this tie, and throughout the first half they had reasons to be confident that they would be adding another win to that record.
Having already tested Belgium goalkeeper Koen Casteels with a speculative Davide Frattesi effort, the away side took the lead after 10 minutes through a combination of slick interplay and sloppy defending.
Giovanni Di Lorenzo’s ambitious one-two with Nicolo Barella should never have made it back to the flying wing-back, but Maxim De Cuyper failed to clear and Di Lorenzo’s deflected cross allowed Sandro Tonali to slot home from close range.
It was the Newcastle midfielder’s first international goal, and his first since returning from his 10-month ban.
Anything but a win would end Belgium’s already slim hopes of qualifying for the play-offs, but a comeback seemed unlikely during a first half where the Red Devils were anonymous as an attacking threat.
They finished the half to a chorus of boos from the stands after managing a single blocked shot at goal and just two touches in the opposition box during a dismal opening 45 minutes.
Under-pressure Belgium coach Domenico Tedesco desperately needed a dramatic improvement from his men after the break, and the Italian had reasons to be hopeful early in the second half, as Zeno Debast and Leandro Trossard forced Gianluigi Donnarumma into his first saves of the game from long range.
In between those efforts, Italy nearly punctured the Red Devils’ momentum but failed to scramble home a second goal from close range, before Di Lorenzo missed a free header from six yards out.
Romelu Lukaku is on his longest run without an international goal since 2018 and wasted his best chance of the night as he flashed a glancing header wide with 10 minutes to go.
It was another header, this time from Wout Faes, that proved to be the last chance for Belgium to grab a point, but the Leicester City defender’s flicked header bounced off the post with Donnarumma beaten.
Italy would hold out against late Belgium pressure to continue their impressive Nations League run while, due to Israel’s unlikely draw against France, Belgium are still not mathematically safe from finishing bottom of Group 2.