Inter Milan playmaker Eriksen collapsed just before half-time of the Group B fixture against Finland in Copenhagen on Saturday, receiving treatment on the pitch before being taken to hospital, where his condition was later reported to have stabilised.
The match was eventually completed, on the request of both squads, with Finland - playing in a first major tournament - going on to win 1-0 with a header from Joel Pohjanpalo as Denmark's Pierre-Emile Hojbjerg saw a penalty saved.
Earlier in Group A, Wales fought back to draw 1-1 against Switzerland in Baku.
Belgium laid down a marker of their champions credentials with a 3-0 win over Russia in St Petersburg to top Group B.
Sunday's other matches will see Holland start their Group C campaign against Ukraine in Amsterdam, while Austria play North Macedonia in Bucharest.
Tweet of the day
With a crowd of around 22,500 expected at Wembley for Sunday's Group D opener, the Football Association has called on England fans to "respect the wishes" of the decision of the players to take the knee ahead of their matches at Euro 2020.
Football united
Football came together on Saturday to offer support to Denmark and wish Eriksen a swift recovery.
Quote of the day
During an emotional post-match press conference, tearful Denmark head coach Kasper Hjulmand praised his players for the courage shown on the most testing of evenings at the Parken Stadium.
Finland mark arrival on the big stage
The Eagle Owls, making their tournament debut, battled to a hard-earned victory - albeit not in the circumstances they would have wanted on an emotional night in Copenhagen.
Stat attack
Romelu Lukaku hit a brace against Russia, paying tribute to his Inter team-mate Eriksen after opening the scoring in the 10th minute. His tally stands at 20 goals in the last 15 competitive matches, making him now Belgium's outright all-time top goalscorer at the Euros.
Up next
June 13:
England v Croatia (Group D, London, 1400)
Austria v North Macedonia (Group C, Bucharest, 1700)
Holland v Ukraine (Group C, Amsterdam 2000)