Denmark's forward Martin Braithwaite, left, vies with Australia's midfielder Jackson Irvine during the Russian Federation 2018 World Cup Group C football match at the Samara Arena in Samara on Thursday.
Nicolai Jorgensen controlled and cleverly flicked the ball inside to Eriksen, who ghosted into space and lashed a sweet half-volley on the rise which flew high into the net.
Yet just as in their opening game, Australia were handed a route back into the match from the penalty spot, thanks to the intervention of the Video Assistant Referee.
The Oceanic side kept creating half-chances as the half played out, and were awarded a penalty in the 36th minute via the VAR system, after Yussuf Poulsen was judged to have handled the ball in the box from a corner.
They won't be the favorites in Samara, either, but after coming so close against the French, Coach Bert van Marwijk only had positive words for his players.
Hareide is not convinced by VAR so far at the World Cup. "He is down to Earth and you wouldn't think that he was as world class as he is".
Mile Jedinak scored from a penalty given after a VAR review as Australia came from a goal down to draw 1-1 with Denmark.
Tottenham man Eriksen opened the scoring with a great strike. "The next game is another game, but it gives us confidence", he said.
Latest odds put Denmark at 10/11, Australia at 7/2 while a draw comes in at 5/2.
A win over the "Socceroos" in Samara on Thursday, combined with Peru failing to beat France, would see Denmark into the last 16 - a feat they have not managed since 2002, when Sorensen was in goal for a 3-0 defeat to England in Japan.
He had originally waved away Australian protests but, despite the ball seemingly hitting Poulsen's arm by accident from Leckie's header, Lahoz pointed to the spot and Jedinak obliged to tuck home the penalty.
Denmark began their World Cup campaign with a hard-fought victory against a Peru side making their first appearance in the competition since 1982.
"We had chances to win and we deserved to win, so I'm disappointed", the Dutchman said.
After the pleas from Denmark's players to the referee went unheard, Schmeichel had a few words with Jedinak to rattle him.