Chile is now topping Group B of the tournament with four points and a goal differential of two.
Cameroon showed promise and scored through Vincent Aboubakar to pull it back to 2-1 after the Germans had taken a two-goal lead, but the African Champions were always up against it, especially when they went down to 10 men after Ernest Mabouka was sent off on 64 minutes.
In the other Group B match, Chile reached the semis with a 1-1 draw against Australia. "But four or five changes are conceivable".
"It was a very intense match, a match that was marked by strategical play and it was very demanding in that sense", Loew said.
Cameroon would have felt more comfortable playing this match against the world number one, if they had defeated Australia in their last match which ended up in a 1-1 draw.
Vargas, who has 34 goals for Chile, nearly added to the lead in the first half with a powerful shot that struck the crossbar. The Indomitable Lions have had a tough time of things in Russian Federation thus far, losing their opening match 0-2 to Chile before drawing 1-1 with Australia on Thursday evening.
"We've done it in tennis, in golf, you name it, the Olympics where we've had world champions and that's what this guy is". The results have left Hugo Broos' team at the bottom of the pool with just one point, trailing co-leaders Germany and Chile by three points.More news: Big cases, retirement rumors as Supreme Court nears finish
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Copa America winners Chile face Australia, who like Cameroon also have just one point from their two games, on Sunday in Moscow.
He maintained his impressive record of steering the national team to the semi-finals of every tournament over the last decade.
After a strong season with Hoffenheim, Demirbay slotted into attacking midfield alongside captain Julian Draxler and Hertha Berlin's Marvin Plattenhardt, who came in for Jonas Hector on the left wing.
Against Australia, the Indomitable Lions took the lead just before half-time, but they gave away a totally unnecessary penalty, and then missed several good chances to win the game. If he plays [on Monday AEST] it's because he has earned it. It was the latest by a Germany goalkeeper in the World Cup warm-up tournament.
Meanwhile, Manchester City goalkeeper Claudio Bravo could play for the first time since April in Sunday's Confed Cup clash against Australia, says Chile's coach Juan Antonio Pizzi.
But, with the two-goal margin required to advance, an Aussie win is no bet at all.
That was the way it stayed until midway through the second half when substitute Martin Rodriguez spared their blushes with the equaliser.