The 34-year-old Swedish striker, who is leaving the Nou Camp this summer to finish his playing days with hometown club Helsingborgs, produced two moments of class to finally unlock Arsenal’s magnificent defence.
First Larsson, a 61st-minute replacement for Mark Van Bommel, conjured up a deft flick for Samuel Eto’o to drive home a thunderous 76th-minute equaliser.
Then the 2001 European Golden Boot winner delivered the pass that released fullback Juliano Belletti into the box, who rifled in the 81st-minute winner.
“It was an unbelievable way for me to finish my career at Barcelona,” said Larsson. “I have had a fantastic experience here in my two years with two league titles and now this. It’s amazing.”
To make the victory even sweeter Barca’s victory also ensured Larsson’s former club Celtic will qualify directly for the group stage of the Champions League next season.
Arsenal skipper Thierry Henry was in no doubt that the Swede’s arrival had been crucial.
“People always talk about Ronaldinho and magic and that but I didn’t see him today – I saw Henrik Larsson. That’s where the magic was,” Henry said.
“Two times he came at us with those little short runs. When he started buzzing around the box he changed the game, that is what killed us.
“Sometimes you talk about Ronaldinho and Eto’o and people like that, you need to talk about the proper footballer who made the difference and that was Henrik Larsson tonight.”
It was the best possible ending to Larsson’s Barcelona career, made all the more unusual by the fact that the Catalans would be keen for him to stay.
“I love playing for Barcelona, I really cherish it,” the man who netted 242 goals in 315 matches for Scottish giants Celtic had said before the match.
“But I’ve been away for a long time. It’s time to go home.”
Before Larsson embarks on the final leg of his glittering career there is one last assignment, the World Cup.
“I feel as fit now as I did ten years ago. The older I get the stronger I get,” Larsson said, who has regained fitness after a horrific knee injury in 2004 ruined his first season at Barca.
Yet while standing behind Ronaldinho, Samuel Eto’o and Lionel Messi in the Nou Camp pecking order, he was a highly valued member of the Catalan squad – a fact underscored by his contribution to Wednesday’s victory.
Barcelona coach Frank Rijkaard is among those who would be happy if Larsson had a change of heart and decided to stay.
“When we need a goal from him, he delivers,” said Rijkaard.
World player of the year Ronaldinho was similarly effusive.
“At Henrik’s age many players announce their retirement from international football but no-one I know his age is at the great physical level Henrik is at right now,” Ronaldinho said.
“He could play at the highest level for a long time.”
Larsson has shown no sign of changing his mind however. “It’s flattering but my decision has been taken. I’m going home this year and that’s that.”