MILLWALL missed the chance to pull clear of the Championship relegation zone as they lost 3-1 to Middlesbrough at The Den.
The Lions went into the match knowing that victory would extend the gap between themselves and third-bottom Portsmouth to nine points, but Marvin Emnes struck twice inside 38 minutes as Kenny Jackett's side made a disastrous start.
Darius Henderson's looping header reduced the deficit on the stroke of half-time, but despite a much-improved showing in the second period, Millwall failed to produce an equaliser.
And Boro subtitute Curtis Main drilled home a killer third goal four minutes from the end to clinch victory for the visitors.
Defeat extends the Lions' winless run on home soil to five matches in all competitions.
Millwall: Forde; Smith, Robinson (c), Lowry, Barron (Dunne 46); Wright (Abdou 46); Kane, Trotter; Feeney (Henry 85), Keogh; Henderson.
Middlesbrough: Steele; Hoyte, Hines, Bates (c), Bennett; Haroun (Main 65), Williams, Arca; Robson (McMahon 87); Emnes (Smallwood 83), Jutkiewicz.