COPENHAGEN, June 21 (Reuters) - Despair turned to exhilaration for Denmark as they claimed an astonishing 4-1 victory over Russia to scramble into the last 16 of Euro 2020 on a head-spinning night in Copenhagen on Monday. Nine days after Denmark"s talisman Christian Eriksen needed life-saving treatment after suffering a cardiac arrest in front of a stunned Parken Stadium crowd, his team mates duly delivered on their promise to "do it for Christian". Needing victory to have any chance of making progressafter losing to Finland and Belgium, it was Eriksen"s replacement Mikkel Damsgaard who lit the touchpaper with a 38th-minute wonder goal, the first act on a night of high drama. When a dreadful mistake by Russia"s Roman Zobnin allowed Yussuf Poulsen to double the lead on the hour, it looked as though fate was smiling kindly on Denmark. It was not that simple as even a win would not have been sufficient had Finland avoided defeat by Belgium, a match bizarrely being played in St Petersburg. The script took a dark turn when Russia"s giant striker Artem Dzyuba converted a penalty at almost the exact moment a Belgium opening goal was being disallowed by VAR. But everything turned out alright in the end as Andreas Christensen"s screamer and Joakim Maehle"slate effort completed the demolition of Russia and Belgium beat Finland 2-0. The stadium erupted and beer filled the air at the final whistle as Denmark remained alive and kicking in a tournament which just over a week ago looked trivial following Eriksen"s brush with death. Denmark, Finland and Russia all finished Group B on three points, behind Belgium, but the Danes edged through on goal difference and can now look forward to taking on Wales in Amsterdam while Russia are going home. They are the first team in the history of the Euros to reach the knockout stage after losing their first two games but it took a while for the message to get through to Denmark"s players, who huddled together in the centre circle around a phone for confirmation of Belgium"s win over the Finns. "It"s so insane that we"ve gone through. This team, these players. It"s great to be a part of it," said Damsgaard, the 20-year-old who has stepped into Eriksen"s boots. "I have never dreamed of being a part of something so big, so it"s a great feeling." MAGIC MOMENT Other than a Pierre-Emile Hojbjerg shot that fizzed wide early on, Denmark were struggling to make much headway against a disciplined Russia side for whom Alexander Golovin could have opened the scoring after a weaving run. With no margin for error, there was a tension about Denmark"s play and Russia had briefly turned down the noise being generated by the 23,000-strong crowd resembling a solid red wall. "It"s the first time I"ve seen support like this," Russia keeper Matvei Safonov said. "One of their players just completes a pass and the whole stadium is on their feet." They were in ecstasy in the 38th minute when Damsgaard produced a moment of magic Eriksen would be proud of. Receiving a pass from Hojbjerg, he took a silky touch with his left foot and opened his body to swerve a majestic right-foot shot beyond Russia keeper Matvei Safonov. If Denmark"s opener was sublime, their second on the hour mark was ridiculous. Zobnin inexplicably played a pass back towards his keeper without looking and Poulsen completed the simplest of tasks to score. Denmark were rampant, but everything went flat as Russia were awarded a penalty after Jannik Vestergaard fouled Alexander Sobolev -- and giant striker Dzyuba thumped the ball past Kasper Schmeichel to revive their hopes. The mood in the stadium became jubilant as news filtered through that Belgium had finally taken the lead and Denmark rode the red wave to finish with a flourish. Christensen latched on to a clearance to smash an unstoppable shot past Safonov from 25 metres before Maehle fired home his side"s fourth to make absolutely sure of a reaching the knockout phase for the first time since 2004.