"Sometimes it's not always the most beautiful basketball," said Nowitzki, who scored 13 of his 19 points in the second half. "We only scored six points in the first quarter, but the good thing was that the defense was good."
France downed host Lithuania 73-67, with Nando de Colo scoring 13 of his 21 points in the fourth quarter. Tony Parker added 19 points for unbeaten France and Joakim Noah had 13 rebounds. France will play Spain for first place in Group E on Sunday.
Germany trailed 26-23 at halftime before regrouping.
"We talked at halftime about how it was one of the worst halves that we have ever played. But we were still only down three points," Nowitzki said. "We saw everything positively, and in the second half we really played as a team and hit some important shots. It was good enough."
Los Angeles Clippers center Chris Kaman had 20 points for Germany. He and Nowitzki had seven rebounds each. Chicago Bulls backup center Omer Asik, coming back from a broken lower left leg, led Turkey with 19 points and 11 rebounds.
Nowitzki, the MVP of the NBA finals after taking the Mavericks past Miami for the title, is trying to take Germany to its second straight Olympics. The two finalists from this tournament will qualify for next year's London Games. The next four teams will go to an additional qualifying tournament.
Germany will need help from others to make the quarterfinals.
"We overcame the first hurdle and now we have to see what the other teams do," Nowitzki said. "I hope that we can have a bit of a final on Sunday and that the place is packed."
Germany must beat Lithuania and hope for Turkey to defeat Serbia. Lithuania's win would leave Serbia or Turkey as the fourth team to progress. Lithuania can't lose big or it can also be eliminated in a three-way tie. Turkey advances if it beats Serbia and Germany loses to Lithuania.
Spain again rode the strength of the Gasols. Pau Gasol had 26 points and younger brother Marc had 20 to go with 10 rebounds. In one stretch in the second quarter, Pau Gasol scored seven points and Marc Gasol added four in an 11-0 run. Spain led by as many as 29.
"To hold a team that's been scoring 80 to under 60 is a great achievement," Spain coach Sergio Scariolo said. "We came in with great concentration and immediately established our high-tempo game. We are still not shooting that great, that's the only problem."
Serbia, led by Nenad Krstic's 12 points, has lost three straight matches but can still advance if it beats Turkey in its final Group E game. Turkey is the only team to have beaten Spain at this year's tournament.
Spain beat Serbia in the European final two years ago, but then lost to the Serbs in the world championship quarterfinals last year. This time, it wasn't a contest.
"They hurt us very badly and we didn't defend as usual," Serbia guard Stefan Markovic said. "Now we have to focus on the last game."
All 12 of Spain's players scored. Serbia was without guard Aleksandar Rasic because of a back problem. Milos Teodosic, the Serbia guard whose 3-pointer at the buzzer beat Spain at the worlds last year, was held to six points.
"We wanted to stop Teodosic and we did it," Spain guard Jose Calderon said.