By Scott Wilson
MILLWALL suffered some last-gasp disappointment as Jordan Hugill's 90th-minute penalty denied them what would have been a deserved win at Middlesbrough.
Neil Harris' side looked set for an impressive away victory after Jed Wallace's first-half strike broke the deadlock at the Riverside.
But despite holding out for more than an hour, Millwall were undone when substitute Steve Morison bundled over Daniel Ayala in the final minute of the game.
Hugill stepped up to convert from the spot, but the Lions will still be pleased with their battling display against a Boro side who remain in the play-off positions.
Ben Marshall was handed a second debut for the Lions after his loan move from Norwich last week, while Ben Thompson made a first-ever Championship start. Thompson played in an advanced position in midfield as Millwall lined up in a 4-3-3 formation.
The two sides were separated by 15 places at kick-off, but you would not have known it from the way in which Millwall dominated from the outset. The visitors were slicker and more purposeful than their opponents from the off, and it was hardly a surprise when they broke the deadlock. In fact, the only shock was that it took them 22 minutes to forge a breakthrough.
With Wallace and Marshall playing either side of Lee Gregory, Millwall attacked with numbers from the very first minute.
Gregory should have opened the scoring early on, but while the ball fell invitingly for him after the Middlesbrough defence failed to deal with Shaun Williams' corner, his close-range shot was saved by an onrushing Darren Randolph.
Gregory went close again shortly after, firing into the side-netting after receiving Wallace's right-wing cross, and he was a central figure as the deadlock was broken midway through the first half.
A swift counter-attack ended with the ball at Gregory's feet, and with Ayala and Danny Batth both being drawn towards him, he was able to slip a square pass to the unmarked Wallace, who calmly steered home a precise low finish, his fourth league goal of the season.
The goal was no more than Millwall deserved, and they almost added another when Thompson headed Williams' left-wing cross straight at Randolph.
Apart from claiming a couple of hanging crosses, Jordan Archer had been by a bystander up to that stage, but he was finally tested seven minutes before the break.
Jonny Howson met Adam Clayton's cross with a powerful diving header, and Archer got down well to turn the ball around the post.
Middlesbrough's players felt they should have had a penalty from the same move, but while Shaun Hutchinson tangled with Hugill as the ball was delivered from the flank, it would have been exceptionally harsh for referee Keith Stroud to have awarded a spot-kick.
Archer became an increasingly influential figure in the second half, with the half-time introduction of substitute Rajiv van La Parra enabling Middlesbrough to increase their attacking threat.
Van La Parra, who joined Boro on loan from Huddersfield at the start of the month, drilled in a 51st-minute shot that Archer got down to save, and the Millwall goalkeeper was called into action again a few minutes later, parrying a fiercely-hit effort from Lewis Wing.
Hugill fired over the crossbar when he should have at least found the target, and Millwall's second-half attacking was markedly less effective than their efforts before the break. That said, however, Marshall threatened midway through the second period with a long-range strike that whistled wide of the post.
The visitors' defending remained impressive, and Boro looked to have run out of ideas as the clock ticked into the final minute.
However, Boro substitute Stewart Downing swung over a cross from the right, and his fellow replacement, Morison, was at fault as he brought down Ayala at the back post.
Hugill stepped up, and Archer had no chance as the Boro striker rolled his spot-kick into the bottom left-hand corner.
Image: Millwall FC