Romain Esse’s first senior goal enabled Millwall to start the new Sky Bet Championship season in style as they claimed a 1-0 win at Middlesbrough.
Second-half substitute Esse, 18, had only been on the pitch for five minutes when he latched on to Aidomo Emakhu’s low cross and his excellent first-time finish found the top corner.
The 79th-minute goal was no more than Millwall deserved given their superiority to that point, with Zian Flemming and Kevin Nisbet also having gone close to a breakthrough.
Middlesbrough, who made the play-offs last season, were disappointing, with their need for additional signings in attack glaringly apparent throughout.
Millwall were the better side for most of the game, with Flemming immediately striking up a decent understanding with fellow forward Nisbet, who joined this summer from Hibernian.
Flemming fired a side-footed effort just wide of the left-hand post in the fourth minute after a neat lay-off from Casper De Norre, and went close again seven minutes later when a short-corner routine involving Joe Bryan ended in him flashing a low drive across the face of goal.
Former Middlesbrough forward Duncan Watmore threatened for the visitors midway through the first half with a shot that was blocked by Paddy McNair.
Watmore was in the thick of the action again nine minutes before the interval as he broke towards the 18-yard box before firing in a shot that looped over the crossbar via a deflection off Dael Fry.
Middlesbrough’s first-half attacking was generally ineffectual, with Millwall’s five-man midfield denying the home side’s players time or space on the ball.
Boro did have the ball in the net in the 39th minute, but it had crossed the byline for a goal-kick before Matt Crooks pulled it back for Hayden Hackney to stab home.
Crooks threatened at the start of the second half, stroking a first-time shot over the bar after Morgan Rogers laid McNair’s cross into his path, but Millwall should really have taken the lead a couple of minutes later when Bryan failed to find the target after Flemming slid over an inviting cross from the right.
With Millwall continuing to carve out the better chances, Boro were indebted to new goalkeeper Seny Dieng for keeping the scoresheet blank on the hour mark.
Watmore released Nisbet through the middle, but Dieng was quick off his line to save the Scot’s shot.
There was nothing Dieng could do when two of Millwall’s substitutes combined to break the deadlock with 11 minutes remaining though.
Emakhu skipped away from McNair to break down the left touchline and, after he slid a low cross into the 18-yard box, Esse curled a superb first-time finish into the top corner.