Goals from Britt Assombalonga and Jonny Howson secured a play-off place for Middlesbrough as they ran out 2-0 winners against Millwall at the Riverside Stadium on Saturday evening.
After showing their attacking prowess in the early stages, Tony Pulis' Boro capitalised on their lively start when Assombalonga struck home via the post after Dani Ayala's speculative pass from defence.
They made it two with 24 minutes to play when Howson walked the ball over the line following Jordan Archer and Jake Cooper's miscommunication when defending Stewart Downing's cross.
The result extends the hosts' season by at least two further games, while the Lions are left with the task of securing a nine-goal swing against Aston Villa at the Den on the final day.
With Brentford, Bristol City and Sheffield United falling from the play-off picture earlier in the day, there was fresh impetus for the Lions to remain within in touching distance of the top six, but a rapid start from the hosts threatened to curtail their hopes altogether.
The effervescent Adama Traore tested the water in the opening stages, but after 12 minutes, Assombalonga put Pulis' side in the driving seat when he brought down Ayala's long ball, turned and struck beyond Archer via the near post.
Millwall's attacking threat was largely subdued and they were fortunate not to fall two behind when Shaun Hutchinson - arguably the bedrock of their success this season - stood strong to block a goalbound effort from Downing.
Boro boss Tony Pulis named an unchanged side from the one that beat Derby 2-1 at Pride Park last Saturday. Ryan Tunnicliffe replaced the injured George Saville for the Lions, while Australian international was retrospectively handed a three-match ban in midweek.
Lately, Championship fixtures really have been a game of two halves for the Lions and it looked as though that would be the case in this fixture as they took the game to their opponents, but a distinct lack of efforts followed.
After 66 minutes, Millwall's momentum received a blow when Howson doubled the lead, and it couldn't have come in a more simple fashion. Cooper and Archer failed to warn one another of their presence, the stopper dropped the ball and Howson sidefooted over the line.
Shaun Williams had the visitors' best chance late on when he glanced a header at Darren Randolph, before Muhamed Besic had a penalty appeal turned down by Paul Tierney.
Man of the match - Muhamed Besic
The Bosnian's eye for a key pass was evident throughout the game and though he didn't directly set up either of Boro's two goals, his hunger and ability to do so was what caught the eye at the Riverside.
His temper flared when referee Paul Tierney waved away penalty appeals after he felt he was brought down illegally inside the area five minutes from time, but it mattered little in the end as Boro secured a play-off place.
Tony Pulis: "Well firstly, Millwall have over-achieved massively this year. They are a team who work really hard, they've got good balance and they make it very, very difficult for you. We approached it in the right manner and, fortunately, got the right result.
"It matters that we now go to Ipswich and do the best we can. That's the next game and then we will look at the situation from there."
Neil Harris: "I thought we gave two really poor goals away. Middlesbrough - with the pace they've got on the counter - won't give the ball away too cheaply, but we've huffed and puffed without really creating too many clear cut chances. That's two games in a row that we've thrown games away in my opinion, but credit goes to Middlesbrough.
"We had a run of games where we felt we could impact the division and during those 17 games we really did. You look at the quality of the teams in the top six and we're one of those teams knocking on the door who just aren't quite going to get there."
Both sides are next in action on the final day of the season as they look to secure a play-off place on Sunday May 6. Neil Harris' Lions face a tough test as Aston Villa visit the Den, while Boro travel to managerless Ipswich. All Championship games get underway in conjuction at 12.30pm.