Sunderland 0 Southampton 4

Seven days after they beat Crystal Palace by a four-goal margin, the Black Cats were on the wrong end of an identical scoreline as their relegation worries intensified at the Stadium of Light.

• Four key talking points, plus Moyes' reaction

Manolo Gabbiadini’s first-half double effectively condemned the Black Cats to their seventh home reverse of the season, with Jason Denayer’s late own goal and a stoppage-time strike from Shane Long piling on yet more agony.

Sunderland were dreadful for all bar the opening 15 minutes, and the result means they remain two points adrift of safety. That gap could increase tomorrow, with Swansea and Leicester both in action.

David Moyes will take his side to New York for a four-day break next week, and on this evidence, the Black Cats boss has plenty to work on if he is to guide his side to safety.

Having watched his side score four goals at Selhurst Park, Moyes understandably kept his tinkering to a minimum. His only change was enforced, with Darron Gibson making his first Sunderland start in place of the injured Jack Rodwell.

The Black Cats had produced their best display of the season at Palace, and for the opening quarter-of-an-hour, they threatened to stage a repeat.

With Didier Ndong controlling the heart of midfield and Adnan Januzaj drifting in a free role behind Jermain Defoe, the hosts dominated the opening stages. Suffice to say, their supremacy was not to last.

Their only real opportunity came to nothing when Defoe was caught flat-footed as Januzaj crossed from the left, but there was a pleasing intensity to their early efforts.

It was not to last. Southampton gradually gained control of the game, with Ryan Bertrand proving especially effective down the visitors’ left flank, and with Sunderland’s defence collapsing in an all-too-familiar fashion, the Saints were two goals to the good by the interval. That a striker called Gabbiadini claimed both of them will have been especially galling to the home fans.

Gabbiadini’s movement had already caused problems when he drifted behind the Sunderland defence in the 26th minute, only for Cedric to slice his pull-back harmlessly wide.

The warning was not heeded however, and Southampton’s new Italian striker claimed the opener four minutes later. Bertrand drove in a cross from the left, Kone missed the ball as he attempted too execute a diving header, and Gabbiadini was able to bundle home from close range.

Video replays proved the striker had converted with his arm, but he was immediately behind Kone and the ball hit him rather than the other way around. Tellingly, no Sunderland defenders appealed against the goal.

The Black Cats were on the back foot from that point onwards, and their task became tougher when they conceded a second goal on the stroke of half-time.

Dusan Tadic fed Gabbiadini in the box, and with Kone standing off him, the £17m January signing spin between Sunderland’s Ivorian defender and his team-mate, John O’Shea, to slot home. It was a wonderful piece of skill from Gabbiadini, but was aided and abetted by some dreadful Sunderland defending.

Moyes needed to change something at the interval, and he responded by bringing on Steven Pienaar for O’Shea and reverting to a flat back four.

However, Sunderland’s struggles continued, and Gabbiadini almost claimed a hat-trick within three minutes of the restart as he peeled off Billy Jones to meet James Ward-Prowse’s corner. He struck his volley cleanly, but Vito Mannone got down well to save.

Mannone was called into action again shortly after the hour mark, beating out a 20-yard shot from Tadic after the Saints midfielder had skipped past Pienaar.

Sunderland had not recorded a single effort on target at that stage, and there were ironic cheers when Ndong finally tested Fraser Forster in the 66th minute with a speculative long-range effort that was easily saved.

Southampton remained the dominant force, however, and James Ward-Prowse twice went close to claiming a third Saints goal. His first effort whistled just wide of the target from distance, while his second saw him head Nathan Redmond’s cross wide of the left-hand post.

Mannone tipped substitute Long’s header over the crossbar with 16 minutes left, and was also forced to save from Redmond as the visitors continued to pour forward in the closing stages.

Southampton finally claimed the third goal they deserved in the 88th minute, with Denayer putting the ball into his own net. Substitute Wahbi Khazri just stood and watched as Bertrand surged down the left flank on the overlap, and when the full-back delivered a dangerous low cross into the area, a sliding Denayer put the ball past Mannone.

There was still time for things to get worse, with Long adding a fourth goal in stoppage time. The striker was afforded the freedom of the penalty area as he played a one-two with Ward-Prowse before slotting home.

Sunderland (5-3-1-1): Mannone; Jones, Kone, O’Shea (Pienaar 46), Denayer, Oviedo; Ndong, Gibson (Khazri 81), Larsson (Borini 58); Januzaj; Defoe. Subs (not used): Mika (gk), Manquillo, Lescott, Honeyman.

Southampton (4-2-3-1): Forster; Cedric, Stephens, Yoshida, Bertrand; Romeu, Davis; Ward-Prowse, Tadic (Hojbjerg 81), Redmond; Gabbiadini (Long 72). Subs (not used): Hassen (gk), Gardos, Sims, McQueen, Rodriguez.