Podgorica - England continued their perfect start to Euro 2020 qualifying with a 5-1 thrashing of Montenegro on Monday, but another impressive victory for the Three Lions was overshadowed by allegations of racist abuse in Podgorica.
Raheem Sterling celebrated the visitors' fifth goal by cupping his ears towards the home fans.
"Best way to silence the haters (and yeah I mean racists)," Sterling tweeted alongside a photo of his celebration.
England manager Gareth Southgate also said he heard racist chants aimed at Danny Rose and promised to report the issue to UEFA.
"I definitely heard abuse at Danny Rose when he got booked at the end of the game. There is no doubt in my mind it happened. We will make sure that is reported to UEFA because it's not acceptable," said Southgate. "We've got to make sure we support our players."
On the field, England showed why their current crop are among the favourites to be European champions next year after Marko Vesovic stunned the World Cup semi-finalists early on.
Michael Keane's header restored parity before Barkley's double either side of half-time put the visitors in command and Harry Kane and Sterling rounded off a comprehensive victory.
Southgate's trust in youth was again rewarded as 18-year-old Callum Hudson-Odoi, who is yet to start a Premier League game for Chelsea, shone on his full international debut, while Declan Rice, 20, was also handed his first England start.
"Fabulous performance," said Southgate on Hudson-Odoi. "With young players it is always up to them. You can see the talent, his application has been excellent. He's got to continue that."
Resilience after conceding
England are not used to falling behind these days, but showed a resilience to bounce back that points a growing maturity despite the tender age of many in the squad.
The home fans were given hope of a massive upset 18 minutes in when Vesovic turned inside Keane and curled past Jordan Pickford.
Keane made amends for his earlier error with a commanding header from Barkley's free-kick on the half hour mark to settle England's nerves.
Nine minutes later, Barkley applied the finishing touch after Hudson-Odoi's positive run into the box and shot which his club teammate turned in from close range.
Only a fine save from Danijel Petkovic denied Hudson-Odoi a goal to go with his full international debut early in the second-half.
Further goals from Barkley, Kane and Sterling did though round off an excellent start to qualifying for England after a 5-0 thrashing of Czech Republic on Friday.
Sterling scored a hat-trick against the Czechs at Wembley, but also played provider as his cut-back broke perfectly for Barkley to coolly side-foot home.
The Manchester City winger then led a rapid counter-attack with only Kane for company and squared for the England captain to tap home his 22nd international goal.
And after scoring just twice in his first 45 caps, Sterling now has six goals in his last four England games as he raced onto Jordan Henderson's through ball before slotting low past the goalkeeper.