Manchester United's American tour ended in a defeat as Neymar ignored speculation over his future to fire Barcelona to victory.
Jose Mourinho's men brought the curtain down on their pre-season trip to the United States as FedEx Field, home of the Washington Redskins, played host to their final International Champions Cup match on Wednesday evening.
Paris St Germain target Neymar netted the only goal of the match in the US capital, securing Barcelona a 1-0 win as United lost their first pre-season game in front of 80,162 supporters.
After 17 days and five matches in as many cities, the Reds return to Europe for friendlies in Norway and Ireland as preparations for the UEFA Super Cup against Real Madrid continue.
United overcame Zinedine Zidane's men on penalties at the weekend, but LaLiga rivals Barca proved a far sterner test as Lionel Messi, Luis Suarez and Neymar impressed in the first half of a match that saw David De Gea shine.
However, the Spain international could do little to prevent Neymar directing home what proved the winner as an entertaining first half made way for a largely pedestrian second period.
Jesse Lingard exiting the field in discomfort will be more of a concern than the result to Mourinho after what was a good test against Ernesto Valverde's Barca.
The Catalans controlled much of the first half, with Neymar and Messi having early attempts before De Gea pulled out a fine, one-handed save to deny Suarez.
Messi clipped the foot of the post from 20 yards in the 12th minute, with United eventually settling and temporarily bossing the play.
Paul Pogba turned from a throw-in and unleashed a spectacular long-range strike that Jasper Cillessen did well to deny, before Romelu Lukaku, Lingard and Henrikh Mkhitaryan had attempts.
Marcus Rashford's determination and close-control allowed him to test Barca's goalkeeper at his near post, but it prove a short-lived period in the ascendancy.
De Gea again had to stand firm to deny Neymar, but the Brazil international soon found the net. Antonio Valencia stumbled when trying to cut out a Messi through ball, with calls for a foul ignored as Neymar slotted home.
Messi whipped a free-kick just over the bar and De Gea again produced a superb stop as half-time approached, with Suarez congratulating the goalkeeper after seeing his acrobatic attempt denied.
Lukaku just failed to get on a drilled cross ahead of the break in which Barcelona made 10 changes, with United a comparatively-restricted five.
Unsurprisingly such widespread alterations took the sting out of the game, with Barcelona dominating possession without creating a clear-cut chance until Paco Alcacer fluffed his lines.
The striker failed to beat Sergio Romero after Anthony Martial bent over at the other end, shortly after coming on as Lingard picked up a knock.
The England international went straight down the tunnel for treatment as his team-mates kicked on, with Andreas Pereira and Pogba trying to draw level.
Further sting was taken out of the play when Marouane Fellaini went down following a challenge from Sergi Roberto as play came to a close.