Full-time: Watford 1 Middlesbrough 0
MIDDLESBROUGH'S barren run now extends to five matches after Troy Deeney's penalty sent them crashing to a 1-0 defeat at Watford.
Deeney converted from the spot at the start of the second half after Ben Gibson fouled Fernando Forestieri, and Gibson's awful afternoon got worse when he was dismissed for two bookings shortly after.
The dismissal made it ten-against-ten as Watford midfielder Samba Diakite had already been sent off for a dreadful foul on Dean Whitehead, but Boro were unable to get back into the game.
The Teessiders have now not scored in more than eight hours of football, and any lingering hopes of a place in the play-offs have surely disappeared.
With Danny Graham lacking support all afternoon, Aitor Karanka's failure to provide adequate support to the Sunderland loanee has proved costly.
Boro made one change from the side that drew with Blackburn last weekend, with Albert Adomah replacing Mustapha Carayol on the flank.
The Teessiders had failed to score in their four previous matches before travelling to Vicarage Road, and their lack of goal threat was apparent throughout the first half.
The visitors were the better side in the opening period, dominating possession and successfully restricting their opponents to a handful of half-chances, However, their superiority dissipated as soon as they entered the final third, with Graham desperately needing more support in attack as he ploughed a lone furrow against the Watford defence.
Grant Leadbitter and Emmanuel Ledesma both failed to find the target with early long-range efforts, before Adomah forced Jonathan Bond into a routine save after cutting in from the left.
Adomah's direct running down the left-hand side was always one of Boro's major attacking assets, and after beating two opponents in the 27th minute, the Ghanaian played the ball to Graham in the box.
The Sunderland loanee enjoyed a profitable spell at Vicarage Road earlier in his career, but his chipped shot sailed harmlessly over the crossbar.
Watford's first effort saw Daniel Pudil prod a low shot well wide shortly before the half-hour mark, but Boro continued to enjoy the upper hand and had the ball in the net seven minutes before the interval.
Jonathan Woodgate headed home Leadbitter's floated free-kick, but the defender was adjudged to be in an offside position and the effort was chalked off.
Shay Given claimed Deeney's looped header shortly after, and the interval arrived with neither goalkeeper having been particularly over-worked.
However, the game changed markedly four minutes after the break as Boro paid a heavy price for Gibson's recklessness.
Forestieri was played into the left-hand side of the area, and as the Italian broke towards the byline, he was felled by a sloppy sliding challenge from Gibson. Deeney stepped up, and casually rolled his 14th goal of the season past Given.
That was a major blow for the visitors, but the pendulum swung again three minutes later as Watford were reduced to ten men.
Diakite went over the top of the ball as he attempted to tackle Whitehead close to the centre circle, and referee Oliver Langford rightly reached for a straight red card.
Graham fired in a shot that was deflected narrowly wide shortly after, but Boro's man advantage disappeared within five minutes of Diakite's dismissal.
Gibson had been booked for a poor challenge in the first half, and the defender received his second yellow card when he attempted to prevent goalkeeper Jonathan Bond from clearing the ball from inside his own penalty area.
After conceding a penalty at the start of the second half, the incident completed a wretched afternoon for the young centre-half.
With the game having been reduced to ten-against-ten, gaps began to appear at both ends, but half-time substitute Mustapha Carayol dragged a 20-yard shot too close to Bond.
Watford should have settled things with 16 minutes left, but after Adomah's dreadful back-header sent him clear, Ikechi Anya pulled his shot wide of the target when he should really have scored.
Boro's final chance of an equaliser came in stoppage time, but after Curtis Main nodded Carayol's cross to Graham, the striker could only loop a tame header into Bond's arms.
WATFORD (3-5-2): Bond; Angella, Cassetti, Doyley (Hoban 46); Faraoni (Anya 64), Murray, Tozser, Diakite, Pudil; Forestieri (Battocchio 70), Deeney.
Subs (not used): Woods (gk), Bellerin, Merkel, Park.
MIDDLESBROUGH (4-2-3-1): Given; Varga (Main 73), Woodgate (Kamara 83), Gibson, Friend; Whitehead, Chalobah; Ledesma (Carayol 46), Leadbitter, Adomah; Graham.
Subs (not used): Konstantopoulos (gk), Hines, Omeruo, Butterfield.