Belgium s Kevin De Bruyne, right, celebrates after scoring the third goal against Germany during the international friendly soccer match between Germany and Belgium in Cologne, Germany, Tuesday March 28, 2023. AP
De Bruyne set up two goals early to give his side a 2-0 lead inside 10 minutes, before scoring one of his own late in the second to deepen Germany's woes ahead of 2024's Euros, which they will host.
Belgium's German-raised coach Domenico Tedesco pushed Yannick Carrasco up front in place of Arsenal's Leandro Trossard and the move paid immediate dividends, with the Atletico Madrid winger blasting in on the counter just six minutes in.
Lukaku, scorer of all three goals in Belgium's 3-0 romp against Sweden on Friday, then smashed in a left-footed effort to put the visitors 2-0 up inside 10 minutes, the goal again assisted by de Bruyne.
With three first-choice central defenders out, a rattled Germany looked all but certain to concede a third.
The introduction of Emre Can, who replaced the injured Leon Goretzka midway through the first-half, brought the home side some desperately needed stability.
Germany were on the board soon after when Niclas Fuellkrug converted a penalty for a Lukaku handball, giving the late-blooming Bremen striker his sixth goal in six international appearances.
Belgium's incisiveness eluded them in the second half as Germany pushed for an equaliser but the home side were unable to break through, coming closest when Timo Werner had a goal chalked off for a clear offside.
De Bruyne sealed the result with just over ten minutes remaining with a one-touch finish assisted by Trossard to complete a memorable captain's knock.
Serge Gnabry gave the home side hope of a draw when he scored with three minutes remaining as Germany went in search of an equaliser but the visitors held on for a morale boosting win ahead of next year's Euros.
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