Robert Lewandowski, Lamine Yamal and Raphinha's second-half goals helped Hansi Flick's side take control after teenager Viktor Dadason had sent the Danish visitors into a surprise early lead.

Substitute Marcus Rashford sealed Barca's victory with a free-kick late on which slipped past Copenhagen stopper Dominik Kotarski.

Five-time Champions League winners Barca struggled to find their rhythm in the first half but did enough after the break to clinch a top-eight league phase finish at a canter.

"We all came here tonight thinking of finishing in the top eight, we're very happy with the win," Yamal told Movistar.

"When they score a goal against you in the Champions League it's very hard to come back, but the team was strong and pulled it off."

Barcelona knew they needed to win to be confident of swerving the play-off round, but fell behind as early as the fourth minute.

A slack pass by Jules Kounde was intercepted and Dadason ran in behind Pau Cubarsi before firing past exposed goalkeeper Joan Garcia.

Spanish champions Barca should have equalised but Kotarski saved from Lewandowski and then pushed away an Eric Garcia effort.

The Barca defender came close again with a long-range effort which smashed against the crossbar.

Three minutes into the second half veteran Polish striker Lewandowski made amends for his first-half miss by pulling Barca level.

Dani Olmo played an inch-perfect ball down the right for Yamal, who cut the ball across for Lewandowski to finish.

Teenager Yamal put Barca ahead after an hour with a deflected effort from the edge of the box. His strike hit Elias Achouri and looped high into the air before dropping into the net.

Barca made the game safe when Lewandowski won a controversial penalty, going down after minimal contact from Junnosuke Suzuki.

Raphinha took the penalty, with his powerful effort beating Kotarski, who dived the right way.

Rashford, on loan from Manchester United, wrapped up Barca's triumph with a free-kick which Kotarki got down to but could not keep out.

It was the England international's fifth Champions League goal of the season, and a sixth nearly followed as his drive from distance cracked against the crossbar.

Copenhagen, who had a late goal from Gabriel Pereira disallowed for offside, finished 31st and were eliminated from the competition.