Leading 26-24, they had given themselves a golden chance of achieving only their second league victory of a torrid campaign.
That is why the final outcome was so difficult to accept. This was Halifax proving they still had the stomach for a fight, but in the end again ultimately coming up short.
Their battling qualities were to the fore during the entire game as they took the lead four times in a see-saw clash.
However, Halifax still produced the same old shortcomings that have blighted their entire campaign.
The tackling was literally hit and miss. When they hit they hit hard but when they missed Southend took advantage with two of their five tries coming from sloppy play, mainly through the centre.
This was Halifax's third long trip in a row yet they showed no signs of being leg weary in an impressive opening spell at Warner's Bridge.
Flanker Dominic Moon started like a man possessed and when he burst through, his only aim was to make the try line. When that avenue was blocked off he shipped the ball wide to winger Ben Mitchell who looked certain to go in at the corner, only to be bundled into touch three yards out.
Moon was not to be denied though as two minutes later Halifax were awarded a scrum five metres from the Southend posts and the former Waterloo forward crashed over, the referee waiting an age before awarding the score.
Joe Knowles was his usual reliable self with his conversion, giving Halifax a 7-0 lead.
Iain Gordon, growing back into the stand off role, produced some superb tactical kicks to keep Halifax on the front foot while the entire team decided to meet anything Southend could throw at them head on and some sturdy defence kept the home side firmly at bay.
Sadly Adam Blades put himself about a bit too much for the referee's liking and when he was dispatched to the sidelines for 10 minutes after incurring the official's wrath once too often, the home side sensed a way back.
They certainly looked dangerous in possession with some fleet-footed backs and powerful centres causing problems every time they ran at Halifax at pace.
But it was the lack of effective tackles that brought the hosts level, winger Andrew Frost breaking through all too easily before bringing centre Elliott Harvey into play, and his slipped ball was meat and drink for flanker Dumisane Meslane, Frost banging over the conversion.
Southend took control as Halifax's early momentum evaporated, Frost and Lewis both getting over the try line only to be brought back for earlier infringements.
But Halifax were still moving the ball around well when they got the chance and edged ahead again when Moon hit the ball at pace. He was tackled short but managed to pop the ball up for Blades, who was by now back in the fold, and he completed an excellent score, Knowles arrowing the conversion wide.
Frost responded with a penalty five minutes later to close the gap, and then Southend took the lead.
Frost again was all but waved through despite Knowles's last ditch effort to cut him off, the winger also adding the conversion.
Halifax refused to dwell on the setback and were in front again less than three minutes later.
Lock Richard White intercepted a pass and made a bee-line for the posts only to realise he was never going to make it.
The only player in support was hooker Will Kay and he didn't fancy his chances in a foot race either so he slipped the ball to scrum half Ronan Dillon, a fine replacement for the departed Craig Aikman. He in turn laid it out to Oli Marns who enjoyed a comfortable jog over. Knowles converted to give Halifax a 19-17 interval lead.
Halifax needed to get a good start in the second half but exactly the opposite occurred with Southend reclaiming the lead almost from the first play, good recycling allowing huge prop Isaac Cook to burst through at pace with nobody standing an earthly of stopping him, Frost converting.
Kay was then held up short as Halifax pressed again, the tackle earning Cook a yellow card, before George Jenkins also went close to getting his name on the scoresheet.
But the pressure was building and when Knowles tried to inject some pace and purpose into an attack, only to be well-tackled, winger Gareth Brear took up the mantle, coming infield, picking up, kicking on and then showing impressive pace to race on to the ball and touch down for a fine individual score, Knowles adding the conversion.
That put Halifax ahead again at 26-24, but with 25 minutes of the game remaining it was clear that there was still more to come from both sides.
Unfortunately for the visitors it was Southend who found their second wind, centre Faapulo Soolefai claiming a try after Halifax believed he had been held up.
Frost added the extra two before replacement Michael Rosam finally found a way past some stubborn Halifax defence to put daylight between the sides for the first time in the game, Frost's conversion killing off Halifax's flagging hopes.

STARMAN:
Just why we're seeing the best of Dominic Moon at this late stage of the campaign is anybody's guess.
The combative flanker continued where he left off against Blackheath with another aggressive display that gained Halifax precious yards.
He used his strength and pace to put Ben Mitchell into a good scoring position that was ultimately foiled, before taking on the responsibility himself for Halifax's first try.
He also broke through to set up Adam Blades for another fine try - and that was before taking his fearless tackling into consideration.
Iain Gordon is another player who has stepped up to the plate in recent games, particularly after taking over from Tom Eaton at stand off.
Gordon is still re-establishing himself in the No 10 shirt and while he has already shown he possesses a fine pair of hands, Saturday's display at Southend also showed that his kicking game could develop into a more than useful weapon.
Gareth Brear became a fully-fledged Halifax player recently after initially arriving on loan from Rotherham.
And while he has taken his time to settle, Brear has shown he has pace to burn and can terrify opposition defences with the ball in hand.
His try on Saturday showed great awareness and not a little skill, sensing the opportunity then putting just enough weight on the kick and backing himself to make up the ground and secure the try.
Moon picks up three points in our season long competition with Gordon earning two and Brear one.

TEAMS:
Southend: Green, Lewis, Soolefai, Harvey, Frost, McKeith, Powell, Williams, Pay, Cook, McLintock, Waring, Meslane, Gill, Connors. Replacements: Legge (Meslane, 68), Rosam (Waring, 60), Guess. Hoult (Green, 72)
Tries: Meslane, Frost, Cook, Soolefai, Rosam
Conversions: Frost (4)
Penalties: Frost
Yellow cards: Cook (49)
Red cards: None
Halifax: Knowles, Mitchell, Marns, McGee, Brear, Gordon, Dillon, Blades, Kay, Jenkins, White, Harrison, Moon, Lewis, Brown. Replacements: Endersby (Brear, 65), Sanderson (Blades, 65), Townsend (Kay, 55), Smith (Brown, 28)
Tries: Moon, Blades, Marns, Brear
Conversions: Knowles (3)
Penalties: None
Yellow cards: Blades (technical offence, 12)
Red cards: None
Referee: Philip Davies (RFU)

PLAYER POINTS:
WORKOUT WAREHOUSE PLAYER OF THE SEASON: 17 Craig Aikman, 14 George Jenkins; 10 Joe Knowles; 11 Gareth Lewis, Matt Harrison; 9 Oli Marns; 6 Dominic Moon; 5 Tom Eaton; 4 Richard Brown; 3 Dave Hall, Danny McGee, James Endersby, Ben Mitchell, Iain Gordon; 2 Richard White, Adam Blades; 1 Phil Skillen, Martin Smith, Gareth Brear.