Michael Owen scored a 76th-minute winner as Manchester United beat European champions Barcelona 2-1 in a pre-season friendly in Washington DC.
In front of nearly 82,000 fans Nani put United ahead in the 22nd minute.
Barcelona, without Lionel Messi, equalised in the 70th minute with a stunning strike from Thiago Alcantara.
Owen latched on to a pass from Tom Cleverley to score the winner as United ended their North American tour with five wins from five matches.
Owen Tweeted after the game: "As normal with Barca, opposing striker hardly gets a touch! That was the case today! Thankfully I scored but I missed a sitter late on too."
United were beaten by Barcelona in the Champions League Final at Wembley in May, and a record crowd for a football match in the American capital saw the Premier League champions gain a small measure of revenge.
Sir Alex Ferguson's side will return home and prepare for the Community Shield against FA Cup winners Manchester City next Sunday at Wembley.
Ferguson's assistant manager Mike Phelan said: "Tonight wasn't a do-or-die situation. It was important that the players we put out on the pitch understand what it takes to play against an exceptional team.
"We have some very good young players out there and [they] proudly conducted themselves to a high standard."
Wayne Rooney missed an early chance before Nani's opening goal was created by Danny Welbeck on a counter-attack. The Portuguese winger beat the offside trap and scored through the legs of Barcelona goalkeeper Victor Valdes.
As well as missing Messi Barcelona chose not to play Xavi, Carlos Puyol or Gerard Pique in their starting line-up. Pep Guardiola's team drew level with 20 minutes remaining when 20-year-old midfielder Thiago scored with a fabulous curling shot that flew past new United goalkeeper David De Gea.
The game would have gone to penalties if it had finished level, but Owen ensured that United left North America with a 100% winning record when he chipped the ball past Valdes following some sloppy defensive play from Barcelona.
Brazilian defender Rafael was injured in the first half and was replaced by his brother Fabio.
Ferguson confirmed after the match that Mexican striker Javier Hernandez was given the all-clear to fly back with the squad after he suffered a concussion in a training session.
"Javier is coming back with us. He is fine. He won't play for a couple of weeks but that would have been the case anyway.
"He was always going to need a break until he got his fitness back. He will do some training, then we will have him back in three to four weeks."
Ferguson also dismissed on-going speculation about the club making an approach to sign Dutch international Wesley Sneijder from Inter Milan, saying: "Absolute nonsense. I have never discussed him. There is nothing new."