Peru created the better chances throughout the 90 minutes and missed a penalty through Christian Cueva, but a second-half strike from Yussuf Poulsen extended Denmark's unbeaten run to 16 matches, as well as ending Peru's 15-game undefeated streak.
With Peru constantly pushing on the Denmark defence, Åge Hareide would have been relying on William Kwist to help sit back while his fellow midfielders pushed further forward in attack.
Denmark last reached the World Cup in 2010 and has five appearances overall.
The referee initially waved Peru's appeals away after Cueva appeared to be tripped by Poulsen but as play continued, the decision was being reviewed and the official eventually halted the action to point to the spot. Cueva then took and missed, hitting it over the bar.
With France firm favourites to top the group and already picking up their first points with a 2-1 win over Australia earlier on Saturday, both Peru and Denmark were desperate for victory to boost their chances of advancing to the playoffs. Midfielder Christian Eriksen is expected to lead the Danes after scoring 11 goals in World Cup qualifying match and a hat trick in the decisive playoff that clinched Denmark's place in Russian Federation.
"They got very little and probably deserved more - sometimes that happens".
The South American nation will face Denmark at noon ET on Saturday in the teams' 2018 FIFA World Cup opener.
And you could hear it from the atmosphere within the ground as the Peruvian fans were loud for the entire 90 minutes of the match, buoying their players on as they gave Denmark a tough ride.
The dead-ball specialist will look to exploit Peru's diminutive team (one of the smallest in the tournament), by providing excellent service to his countrymen (some of the tallest in the tournament).