The result saw Marco Silva's side crowned champions while two goals from Aleksandar Mitrovic took his Championship goal tally for the season to 43.
The heavy loss meant Sheffield United moved above Fulham into fifth and gave Boro further incentive heading into the final day this weekend. Chris Wilder's side are two points behind Luton and the Blades and will need to win their game at Preston North End and hope that one of the sides in fifth and sixth drop points.
Middlesbrough's goal difference is +12, while Luton's is now +7 meaning that a Boro win coupled with a Luton draw against Reading will guarantee Wilder's side a top-six place. Sheffield United's goal difference is +14, giving them more leeway if they were to draw against Fulham in their final game this weekend.
At Craven Cottage, Tom Cairney opened the scoring in the 29th minute – the Cottagers’ 100th league goal of the campaign – and Kenny Tete made it two 10 minutes later to ensure the hosts, who sealed promotion to the Premier League on April 19, were in control at the break.
The floodgates opened in the second half with goals from Fabio Carvalho, Bobby Decordova-Reid, substitute Jean Michael Seri and a brace from Mitrovic – confirming a record haul in the second tier for the Serbia striker.
It marked the third time this term that Marco Silva’s side have netted seven goals.
Play-off hopefuls Luton, who fielded emergency loanee Matt Ingram in goal in place of the injured James Shea, mustered the first chance of the game when Kal Naismith drove forward from midfield and forced a smart save from Marek Rodak.
It was not a sign of things to come, however, as Fulham soon asserted themselves to return to the Premier League as second division champions.
Ahead of the final weekend of action, data experts at FiveThirtyEight have predicted how the final Championship table will look...
Middlesbrough's goal difference is +12, while Luton's is now +7 meaning that a Boro win coupled with a Luton draw against Reading will guarantee Wilder's side a top-six place. Sheffield United's goal difference is +14, giving them more leeway if they were to draw against Fulham in their final game this weekend.
