Kasper Hjulmand's side thought they had broken the deadlock against Tunisia in Group D on Tuesday, but were denied as Cornelius' shot attempt failed to hit the target.
Advertisement
As the tie entered into the final 20 minutes at 0-0, Manchester United star Christian Eriksen stood over a corner for his country.
It was met by Andreas Christensen, who then knocked it towards Cornelius who stood in the perfect position to send it goal bound.
Advertisement
But rather than running off to celebrate finally opening the scoring, Denmark were left with their hands on their head in shock as the ball ricocheted off the right-hand post.
Tunisia looked the more likely to score for most of the game and a brilliant chance just after the break.
Issam Jebali chipped the ball to Aissa Laidouni, but his decision to pass it to Anis Ben Slimane instead of going forward alone was the wrong one as the ball was cut out.
Then, at the death, Denmark thought they had the chance to snatch all three points as a potential hand ball in the box was sent to review for VAR.
Advertisement
However, upon review, the referee opted not to award it.
Advertisement
There had been 14 shots at goal from corners in the match, the most in any World Cup game on record.
Advertisement
But besides both sides having plenty of opportunities, neither could break the deadlock in the opening match of Group D.
The 0-0 draw leaves the countries joint top, with France and Australia set to play later.