Southend were unable to halt Sunderland’s momentum as they fell to a 3-0 defeat at the Stadium of Light thanks to goals from George Honeyman, Chris Maguire and Aiden McGeady.
Both sides created chances early but the game suddenly came to a halt when Ben Coker went down with a serious looking knee injury which required him to leave the field on a stretcher.
After the stoppage, Sunderland would go on to break the deadlock through Honeyman, whose glancing header sneaked in at Mark Oxley’s far-post just before the half-hour mark.
Southend had chances to level before the interval but couldn’t take advantage and they went into the break furious at not being given a penalty for a foul on Dru Yearwood.
And after the break, Sunderland would capitalise on that frustration with a thunderous strike from Maguire, that left Oxley with no chance, doubling the home side’s advantage.
Try as they might, Blues couldn’t get a goal back to start any sort of comeback, with Sam Mantom’s close-range header – which was well saved by Jon McLaughlin – the best they could muster.
Sunderland would then wrap up the points with 10 minutes remaining when substitute Aiden McGeady carried the ball forward and fired beyond Oxley to secure the Black Cats' fourth straight win.
That fourth maximum in a row for Jack Ross’ side kept them within touching distance at the top while Southend slipped the 11th in the table ahead of another tough trip to Barnsley next week.
It was always going to be a tough ask for Chris Powell’s Blues against a Sunderland side who just two seasons ago were playing in the Premier League.
But Southend would have travelled to the Stadium of Light with some confidence having won five of their last seven league games, including Tuesday night’s 3-0 defeat of Walsall at Roots Hall.
Following the win against the Saddlers, Blues made two enforced changes with injuries to Tom Hopper and Harry Lennon meaning they missed out, leaving Simon Cox and former Sunderland defender Michael Turner to come in for Southend.
Sunderland came into the game off the back of three straight away wins in the league and were riding high near the top of the table, and in front of another 30,000-plus crowd at the Stadium of Light they made a bright start.
Mark Oxley had to be at his best as early as the third minute when Jerome Sinclair was picked out by a left-wing cross. The Black Cats number 17 got a header in at the near-post which looked to have the beating of Oxley but the Blues keeper stretched a right-hand out to tip it away superbly.
After that early scare, Blues started to grow into the game and carved out a good chance through Dru Yearwood who shot over from a corner before Taylor Moore got on the end of a Sam Mantom free-kick to head wide.
But Blues’ momentum was suddenly curtailed by a freak injury to Ben Coker who had to be taken off on a stretcher after appearing to badly twist his knee. After a simple clearance to touch, the full-back screamed in agony as soon as his foot landed and with that his game came to an end.
After a long stoppage in play to attend to Coker, Sunderland regained the impetus in the match and their pressure would tell just before the half-hour mark when they opened the scoring through the head of their captain, George Honeyman.
The Black Cats skipper was picked out inside the area by a right-wing cross from Lynden Gooch, with Honeyman expertly glancing his header across the face of goal and inside the far post to give the home side the lead.
Sunderland’s lead was arguably deserved on the balance of play, but Chris Powell’s side almost responded immediately. Harry Bunn carried the ball through a couple of challenges to force a smart save from Jon McLaughlin before Simon Cox shot over from the follow-up.
Southend continued to push and would end the half strongly, and they had a clear shout for a penalty go a begging when Yearwood barrelled his way into the penalty area before being brought down by Tom Flanagan, but the referee waved the protests away as Sunderland went into the break 1-0 up.
Blues knew that the next goal would be pivotal if they were to get anything out of their trip to the North East but they fell further behind early in the second-half following a wonder-strike from Chris Maguire that doubled Sunderland’s advantage.
A loose pass from Moore was picked off by Maguire 30-yards from goal, allowing the Black Cats number seven to carry the ball forward and fire into the top corner, leaving Oxley no chance and leaving Blues with a proverbial mountain to climb.
It just looked like it wasn’t going to be Southend’s day when Sunderland ‘keeper McLaughlin pulled off a smart reflex save to deny Sam Mantom from halving the deficit with a close-range header, with the ball not falling quickly enough for Cox to put the rebound away.
And Blues’ fight was all but extinguished with little over 10-minutes remaining as Sunderland increased their lead to three. Aiden McGeady, on as a sub, picked the ball up outside the area before firing past Oxley for Sunderland’s third, wrapping up another three points for the Black Cats.
Sunderland XI: McLaughlin, Matthews, Cattermole, Maguire, McGeouch (McGeady 54’), Honeyman (C), Gooch (O’Nien 74’), Flanagan, Baldwin, James, Sinclair (Maja 57’). Subs Not Used: Ruiter, Oviedo, Ozturk, Mumba
Blues XI: Oxley, Coker (Hendrie 21’), Turner, Dieng, Cox, McLaughlin (McCoulsky 66’), Yearwood (Kightly 78’), Mantom (C), Moore, Demetriou, Bunn. Subs Not Used: Bishop, Bwomono, Robinson, White
Referee: Mr R Lewis
Assistants: Mr D Street & Mr R Atkin
Fourth Official: Mr K Mulraine
Sunderland: George Honeyman 29’, Chris Maguire 53’, Aiden McGeady 80’
Southend United: None
Sunderland: Tom Flanagan 45+4’
Southend United: Harry Bunn 41’, Dru Yearwood 68’
Attendance: 30,894 (1,130 Away)