The Swedish national team striker, who played the entire match for the Spanish big club, first served Aitana Bonmatí with a pass diagonally backwards in the 57th minute and the Spaniard put 3-0.
In stoppage time in the second half, Rolfö hit a similar set in the ball to the Swiss Ana-Maria Crnogorcevic who set the final score to 5-0.
After four straight victories in as many matches in Group C, Barça has secured promotion to the quarter-finals despite two matches remaining.
Group runner-up Arsenal, who later on Wednesday night meet Danish Køge, is six points behind the reigning Spanish champions with one match less played.
German Hoffenheim is third in the group with three points in four matches.
MORE FOOTBALL: Rolfö goal scorer for Barcelona (October 14)
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Fridolina Rolfö sets the lead goal for Barcelona against HB Köge.
Photo: Youtube