The French international, who joined Barca from Arsenal last month, had a last minute penalty parried by United's Polish keeper Grzegorz Szamotulski, but slammed in the rebound.

Barcelona manager Frank Rijkaard revealed it was Henry's decision to rule himself ready to make his debut. The Frenchman came on for Samuel Eto'o for the second half.

"We have seen he is an intelligent player and we have seen some good passes," Rijkaard told reporters. "We have to take into account he has not played for a long time and it was his decision to go and play. He played well."

Henry had only been on the pitch for 25 seconds when he fired a 16-metre shot narrowly beyond the right post.

Barca came close to a first half opener with a 25-metre free kick from Ronaldinho [Images] which slammed high against the far post in the 18th minute.

Photograph: David Moir/Reuters