Even missing star forward Cristiano Ronaldo, out with a reported bee sting, Portugal were too strong for Croatia in Porto.

Joao Cancelo, Diego Jota, Joao Felix and Andre Silva gave the defending champions a winning start to Group A3 despite Bruno Petkovic's consolation.

The other game saw Kylian Mbappe strike for France in a 1-0 win over Sweden in Stockholm.

Belgium won 2-0 in Denmark in Group A2 after England's earlier 1-0 triumph in Iceland.

Ronaldo would have been looking for his 100th international goal had he played but without him Portugal racked up - and missed - chance after chance against Croatia, who looked a long way from the side who reached the 2018 World Cup final.

"I thought the players could give this performance given how they performed during the week, but it was difficult to guess," said Portugal coach Fernando Santos.

"We were up against great opponents and we delivered at 100 percent."

It is not clear if Ronaldo, who watched from the stands, will be available when Portugal visit Sweden on Tuesday with their hosts looking to recover from defeat to France.

Mbappe took the break of the ball after attempting to beat two players wide left and squeezed his shot past keeper Robin Olsen from a tight angle in the 41st minute.

France next host Croatia in a repeat of their World Cup glory game from two years ago in Moscow.

England returned from their international coronavirus shutdown with a converted and missed penalty in the dying minutes giving Gareth Southgate's side a 1-0 win victory at Iceland.

This tie, like all the other games, was played behind closed doors due to the coronavirus as international football begins a hectic conclusion to 2020.

England looked set for a disappointing draw having failed to turn the lion's share of possession into chances.

England next visit Copenhagen while Belgium host Iceland after starting with victory way to Denmark.

Jason Denayer converted a near-post corner from Dries Mertens in the ninth minute to give Belgium the lead in Denmark and Mertens himself sealed the points late.

It was Denmark's first home loss in nearly four years to a Belgium side which impressed even without Eden Hazard, Kevin de Bruyne and Thibaut Courtois.

Montenegro top Group C1 as Stevan Jovetic's second half double earned a 2-0 win at Cyprus while Luxembourg edged 10-man Azerbaijan 2-1.

In C2 Georgia won 1-0 at Estonia after North Macedonia won 2-1 against Armenia with all goals coming from the spot.

And in the opening game of the three-team Group D2, Graeme Torrilla secured a 1-0 win for Gibraltar against San Marino.

Australian Associated Press