It's been a long time coming but Chester announced their return to the FA Cup first round proper with a magical result against League Two opponents.

Craig Mahon, whose wife gave birth to twins the day before, got the winning goal to ensure he will be the man making the headlines but this was a team effort.

None of the 4,000 or so inside Roots Hall will dispute that the Blues deserved to go through and it was a performance filled with heart, courage and endeavour.

Ben Heneghan gave them the lead on five minutes with his third of the season but Barry Corr replied from the spot on 31 minutes in an entertaining first period.

Mahon marked a memorable 24 hours with the second six minutes after the restart and what followed was a defensive masterclass as the Blues battled hard under intense pressure to seal a tremendous win.

Chester had not featured in the first round since 2010 and had never been this far in the competition as a reformed club.

Stockport put up a good fight in the fourth qualifying round but the Blues came through that and travelled to Essex without the weight of expectation upon them.

Steve Burr accepted his side were the underdogs but he has masterminded upsets before and fancied his chances of pulling off another.

He would have to do it without suspended duo Michael Kay and Matty Hughes, starting a three-game ban after his red card in the 3-2 loss at Eastleigh.

Peter Winn came into the side and Mahon shook off an ankle knock to start with academy graduate Ben Greenop on the bench.

Southend had gone five games without a win before a 2-1 success at Mansfield Town, a result that pushed them into the League Two play-off places.

Phil Brown's men, who reached the fourth round last season, have struggled for goals but were strong favourites to progress past the Blues.

Barry Corr, John White and Luke Prosser give experience to a squad that contains a handful of homegrown talents and promising youngsters borrowed from Premier League neighbours.

Brown knows Chester well from his days as a fullback with Hartlepool, Halifax, Bolton and Blackpool and used his programme notes to reiterate he would not be underestimating them.

Southend started on the front foot with Kieran Charnock making an important block in the second minute but the home side soon found themselves behind.

Mahon was bundled over on the right wing on five minutes and Winn swung the free kick into the box where Heneghan climbed highest and keeper Daniel Bentley couldn't keep his header out.

Chester would have expected a response and the Shrimpers put them under pressure for the next 10 minutes with Corr having two half chances.

David Worrall sliced a shot wide and Myles Weston had Jon Worsnop flying through the air as the hosts kept pressing but the Blues worked hard to keep the lead intact.

Craig Hobson held the ball up well to give John Rooney sight of goal on 21 minutes but his 25 yard shot was comfortable for Bentley before Hobson had a clearer chance after Mahon rolled him into space but Bentley got down well to save.

Worsnop was forced into action when he denied Myles Weston at point-blank range but the home side equalised on 31 minutes from the penalty spot.

White exchanged passes with Worrall before Rooney hauled the right back down from behind to leave referee Graham Horwood with a simple decision to make.

Rooney was booked for his ill-advised challenge and Corr sent Worsnop the wrong way to get his side back on terms.

Southend had the greater possession but didn't create too much and it was the Blues who came closest to getting another before half time.

Rooney curled a low cross into the box and the ball evaded everyone except Gary Deegan, who poked off the line to ensure the scores remained level.

Southend had a great chance in the opening minute of the second period when Jakub Sokolik blasted over but again Chester were the ones to find the breakthrough.

There didn't look to be much on when Heneghan found Mahon with a short pass on 51 minutes but the little winger cut inside and fired a low shot past Bentley from 20 yards.

As in the first half, the home side mounted a response with Worrall fizzing inches wide before Worsnop made a fine save from the same man's diving header.

Brown made a double change on the hour although his decision to replace Worrall upset the home fans and Chester brought on Ibou Toray when the unfortunate Winn left the pitch on a stretcher.

Southend began to exert some serious pressure and dominated the final half hour but the Blues defended manfully and were in no mood to give up the lead for a second time.

Charnock and Matty Brown were magnificent in central defence although sub Jack Payne came within inches of breaking the resistance with a curling shot that had Worsnop beaten.

Jamie Menagh replaced the excellent Mahon for the final few minutes as the Blues continued to find themselves pinned back but Burr's men clung on for a deserved win and a place in round two.

Chester FC: Worsnop, Heneghan, Brown, Charnock, G Roberts, Rooney, James, Mahon (Menagh 86), McConville, Winn (Touray 66), Hobson.

Subs: C Roberts, Greenop, Riley, Harrison, Disney.

Goals: Heneghan 5, Mahon 51.

Booked: Rooney, Hobson, Heneghan, Touray.

Southend United: Bentley, White, Prosser, Sokolik, Williams, Timlin, Deegan (Coulthirst 61), Leonard, Worrall (Hurst 61), Corr (Payne 71), Weston.

Subs: Smith, Atkinson, Bolger, Clifford.

Goal: Corr 31 (pen).

Booked: Sokolik, White, Williams, Timlin.

Referee: Graham Horwood (Bedfordshire)

Attendance: 4,047.