For perhaps the first time going into a tournament, England's players seem ready for top-level global football and while Gareth Southgate's own coaching methods must take some of the credit, the improvement thanks to world-class club coaching can not go ignored.
We hear from the England manager as well as Jordan Henderson and Trent Alexander-Arnold who reflects on his debut.
The man who launched England's World Cup qualifying campaign with the victor in Slovakia 18 months ago, has been on stand-by for the past fortnight.
His Manchester United connections led to a few comedy boos when his name was read out over the PA system, but Rashford won the Leeds faithful over as early as the 13th minute when he gave England the lead in emphatic fashion.
The 20-year-old's display seemed in stark contrast to those he delivered for his club for much of 2018, which prompted speculation about his future given his apparent lack of suitability to Jose Mourinho's plans .
And Rashford admitted afterwards that this was his best game in an England shirt.
"I felt I did the right thing coming and training with England but it has not been easy", said Lallana.
I said to all the team before the game, I expect to see mistakes tonight and, if I don't, there might be a problem because we wouldn't be being as attack-minded as we want to be.
However, there was a gulf in class even between Southgate's largely second string line-up and the Central Americans as England dominated.
Costa Rica face tournament favorites Brazil as well as Serbia and Switzerland in Group E, and will need to show far more ambition once they get to Russian Federation if they are to replicate their heroics of four years ago.
England's Jack Butland (left) is substituted for team-mate Nick Pope during the International Friendly match at Elland Road.
And with 15 minutes remaining, Danny Welbeck capped off the win with a good instinctive header following Dele Alli's cross.
Gareth Southgate's men begin their World Cup campaign against Tunisia in Volgograd on June 18, a game you can hear live on talkSPORT.