Stern John opened his account as Sunderland's promotion charge continued at the expense of Coca-Cola Championship strugglers Southend at the Stadium of Light.

David Connolly opened the scoring in the fourth minute and Swedish winger Tobias Hysen doubled the advantage nine minutes later to effectively seal another precious victory for Roy Keane's in-form side.

But the final say went to Trinidad and Tobago striker John, who found the net twice in as many minutes in the closing stages of the game to claim his first goals since a recent move from Coventry.

This was Sunderland's sixth win in their last seven league encounters and further enhanced their burgeoning promotion credentials.

The result was never in doubt from the moment Connolly clinically dispatched his eighth goal of the season following a £1.4million switch from Wigan last August.

Trinidad and Tobago winger Carlos Edwards crossed from the right flank and Connolly calmly sidefooted the ball past Darryl Flahavan.

It was just the start Keane's men needed and such is the confidence coursing through his side that it did not take long for their second to arrive.

Hysen showed delightful footwork to latch on to Connolly's neat pass before skipping around Lewis Hunt and hitting a fierce shot which flew into the net.

The Wearsiders dominated Steve Tilson's side and their stylish display served to confirm the remarkable turnaround in fortunes engineered by Keane since his appointment last August.

Midfielder Liam Miller played a neat one-two with Dean Whitehead and smashed a shot against Shrimpers defender Peter Clarke.

The hosts went close seven minutes before the break when John headed goalwards to force Flahavan into a fine tip-over save.

To their credit, Southend refused to surrender and came out fighting after the break.

The Essex club arrived on Wearside having collected seven points from their past three games, which included a shock 3-1 win at Birmingham and a stunning 5-0 demolition of relegation rivals QPR.

They were willing enough but Sunderland's extra class always looked likely to prevail as the second half wore on - and so it proved.

Edwards narrowly missed the target in the 70th minute, but John showed them how to do it as he struck in the 77th and 78th minutes.

His first arrived when Whitehead swapped passes with Connolly and hit the ball against a post.

The rebound and fell to John, who tucked the ball away from 12 yards with the minimum of fuss.

And seconds later he had his second as he buried Miller's cross with a 12-yard shot which confirmed Sunderland's dominance.

John scored 29 goals in 74 starts for Coventry but fell out of favour at the Ricoh Arena this season.

With displays like this, he could prove Sunderland's most potent weapon in their quest to avoid the lottery of the play-offs and claim an automatic promotion spot.

Teams:

Sunderland Fulop, Simpson, Nosworthy, Evans, Collins, Edwards,Whitehead (Leadbitter 82), Liam Miller, Hysen (Stokes 72),Connolly (Wallace 71), John.

Subs Not Used: Ward, Yorke.

Booked: Whitehead.

Goals: Connolly 4, Hysen 13, John 77, 78.

Southend Flahavan, Hunt, Clarke, Sodje, Hammell,Gower (Foran 68), McCormack (Moussa 68), Maher, Campbell-Ryce,Bradbury (Harrold 69), Eastwood.

Subs Not Used: Francis, Collis.

Booked: Clarke, Maher, McCormack.

Att: 33,576

Ref: N Swarbrick (Lancashire).