Middlesbrough made a nonsense of Howard Wilkinson's bizarre assertion that his Sunderland side are not engaged in a relegation fight to complete a second successive Premiership double over their derby rivals.

Plain and simply, the Black Cats are entrenched in a life-or-death battle to preserve their top-flight status with only 10 games in which to do so, and on the evidence of this pitiful display, the die is already cast.

The irony that it was transfer-window signings Chris Riggott and Malcolm Christie who did the damage will not be lost on Sunderland fans who saw only Moroccan defender Talal el Karkouri added to a demoralised squad during January.

Defender Riggott put the visitors in the driving seat with a rare double inside seven first-half minutes, and although Kevin Phillips gave the Wearsiders hope with a superb 56th-minute strike, Christie pounced on a blunder by Kevin Kilbane to make it 3-1 three minutes later.

Large sections of the crowd started to head for the exits long before the final whistle as Wilkinson was left in little doubt about their emotions, and he will have some difficulty in persuading them that there is still hope.

Five of their remaining games will be played at the Stadium of Light, where they have now lost their last three in the Premiership, and with Chelsea, Newcastle and Arsenal among the visitors, things could yet get much, much worse.

It was Boro's first Premiership win away from home in 10 attempts since September 28, but they were good value for the points and will now look for a strong finish to a season which had started to slip away from them.

The omens for a bright attacking game were never particularly promising with the Black Cats not having won at home in the league in four attempts and Boro having ended a run of eight successive away games without scoring a single goal with a draw at Liverpool last time out.

Sunderland's own goal-shyness and Boro's renowned defensive solidity suggested that a bore draw was on the cards, but that prediction was blown out of the water with less than half an hour gone as what little enterprise the Wearsiders had was crushed.

Jody Craddock's fifth-minute header from a Michael Gray free-kick, which landed in Mark Schwarzer's arms, raised the hopes of the home fans at the Stadium of Light, but it was one of only two efforts on target they managed to muster before the break.

By contrast, the Teessiders played with a fluency and control which rekindled memories of their blistering start to the season, and when the chances came, they took them with some aplomb.

The only surprise was that it was Riggott who found himself in the right place at the right time as the home defence twice fell victim to set-pieces.

Thomas Sorensen pulled off an excellent save to keep out Christie's goal-bound header from a 21st-minute Geremi corner, but his former Derby team-mate was on hand to smash home the rebound.

And lightning struck once again seven minutes later when hesitancy inside the Sunderland penalty area allowed Jonathan Greening to lift the ball back into the danger zone, and when Gareth Southgate's shot came back off the post, Riggott stepped in once again to make it 2-0.

The travelling fans wasted no time in starting the taunts and fighting briefly broke out in the stands.

But the home fans who decided to watch events off the pitch rather than on it perhaps chose wisely as Stuart Parnaby whistled a volley just wide and Michael Ricketts was only inches away from getting a touch to a Christie cross with the Black Cats all at sea.

Matt Piper replaced David Bellion at the break and the former Leicester midfielder briefly threatened to make an impact, but it took a moment's inspiration from Phillips to get his side back into the game.

There seemed little on when he picked the ball up 35 yards from goal on 56 minutes, but after shifting it on to his right foot, he thumped an unstoppable shot past Schwarzer and in off the post.

The home fans among a crowd of 42,134 settled down for an anticipated grandstand finish, but their hopes were dashed within three minutes when Kevin Kilbane pressed the self-destruct button.

His mishit backpass put Christie in on goal, and he drew Sorensen before sliding his left-foot shot into the bottom corner to effectively end the Black Cats revival.

Wilkinson belatedly introduced crowd favourite Julio Arca in place of out-of-sorts skipper Michael Gray, but it needed a miracle worker to rescue the Wearsiders with just 18 minutes remaining.

Boro defended resolutely, although with few scares, to see out time and clinch the victory their performance so richly deserved.

Teams

Sunderland Sorensen, Wright, Craddock, El Karkouri, Gray (Arca 72), Bellion (Piper 45), McAteer, McCann, Kilbane (Proctor 84), Phillips, Flo.

Subs Not Used: Macho, Babb.

Booked: Wright, Kilbane.

Goals: Phillips 56.

Middlesbrough Schwarzer, Cooper, Southgate, Riggott, Parnaby, Boateng, Greening, Geremi, Queudrue (Murphy 76), Ricketts, Christie (Nemeth 82).

Subs Not Used: Crossley, Job, Maccarone.

Booked: Queudrue.

Goals: Riggott 21, 28, Christie 59.

Att: 42,134

Ref: M Halsey (Lancashire).