Germany struggled against their underdog hosts -- ranked 97th in the world -- but victory kept them on track to qualify for next year's tournament in North America.

The four-time World Cup winners are level on points in Group A with second-placed Slovakia, who beat Northern Ireland 1-0 at home, but have a better goal difference with one match left to play.

The top two face off in Leipzig on Monday with Germany guaranteed direct qualification if they avoid defeat.

Before Friday's match, Germany coach Julian Nagelsmann backed Woltemade to make a difference in Luxembourg, and the big Newcastle striker did exactly that.

After scoring the only goal in a win over Northern Ireland in October -- his first in international football -- the 1.98-metre-tall Woltemade delivered again for a Germany side missing forwards Kai Havertz, Jamal Musiala, Niclas Fuellkrug, Tim Kleindienst and Karim Adeyemi.

"We weren't good in the first half. We moved the ball around too much and into situations where we put ourselves under pressure," Woltemade told Germany's RTL network after the match.

"We did better in the second half," Woltemade said.

"I know it wasn't a pretty game but we gave our all, pushed hard and got the three points."

- 'Punished mercilessly' -

Luxembourg coach Jeff Strasser lamented his side's "failure to reward ourselves" after an impressive opening period.

"We were punished mercilessly. A team like Germany, with that quality, takes advantage of mistakes like that," he added.

A Germany return failed to spark misfiring Liverpool midfielder Florian Wirtz into form.

He had a shot deflected over the bar in the opening half and struggled to make an impact on the game.

Without a point from their opening four group stage fixtures, Luxembourg had the better chances in the first half while injury-hit Germany lacked fluency.

Home winger Daniel Sinani screwed a shot just wide with 21 minutes gone and forced goalkeeper Oliver Baumann into a desperate save from a corner on the half-hour mark.

A visibly frustrated Nagelsmann stormed down the tunnel at half-time and whatever he said elicited a reaction early in the second half, with Woltemade making the breakthrough four minutes after the break.

Leroy Sane, playing his first match for Germany since moving to Galatasaray in the summer, cut a pinpoint cross into Woltemade's path from the right, and the Newcastle striker tapped home.

Sane was key in Woltemade's second with 69 minutes gone, feeding the ball to Ridle Baku, who slid in Woltemade to scoop home.

Describing his return as "an honour", Sane told RTL: "I'm happy I was able to get an assist and repay Julian's trust to some extent."