Four goals, three efforts hitting the woodwork, the Blades coming back from two down and a first ever draw between the sides were the highlights from today's encounter.
Jose Baxter and Neill Collins - on his 200th appearance for the Club - were United's scorers.
The Blades applied the pressure in the second half and hit the woodwork three times but were unable to get in front.
The main pre-match news was that Long kept his place in goal after consecutive clean sheets in cup competitions, whilst before kick-off there was an impeccably-observed minute's silence for victims of the Paris atrocities.
With the rain falling heavily, both sides also had to contend with the conditions as well as each other and that was a contributory factor to a slow start. In the opening 20 minutes, Atkinson powered a shot wide for the visitors, whilst Campbell-Ryce cut inside two defenders from the left before curling over the crossbar.
The Blades were then stung with two Southend goals inside as many minutes, around the half hour mark. Firstly, Long punched away Hurst's corner but the unmarked LEONARD fired back a 25-yard half-volley, which found the net via a post. The home side were still recovering when Coker played inside to PAYNE, who shot across Long and into the far corner of the net.
A number of crowd members voiced their displeasure but United were quickly back on the offensive. Bentley would have been delighted to hear the referee's whistle when he dropped a Harris cross into his own net under pressure from Adams.
However, within a minute, United had halved the visiting side's advantage. A Coutts corner was only half cleared and just as Bentley was about to drop on the ball, BAXTER poked the ball between the goalkeeper's legs.
Three minutes of added time was announced at the end of the first period and Sharp played the ball into the path of Adams, who saw his shot deflect off Thompson and sail over the crossbar. Fortunately, though, United levelled from the resulting corner. Baxter's original delivery was half-cleared but recycled to the number 11, who crossed left-footed for COLLINS to calm control before slotting home.
It was the final action of an action-packed first period.
With the Kop in full voice at the start of the second half, United began well. From a Campbell-Ryce cross, Adams was crowded out and a Sharp shot was blocked, whilst Hammond's effort, after an Adams lay-off, was deflected wide.
Worrall's flicked header from Atkinson's cross was wide of Long's goal but United were enjoying the lion's share of possession, although the visitors were protecting Bentley well. On 69 minutes, though, the goalkeeper was called upon to rush out and save from Sharp after good work from Hammond and Adams.
United then hit the woodwork twice in the space of a minute. Baxter's 20-yard shot struck Bentley's right post and was cleared to safety and in the next move, after Campbell-Ryce was fouled, Baxter's free-kick saw Basham's flicked header shave the left post.
The final ten minutes began with United winning a number of corners and Southend defending for their lives, although, on the break, Atkinson and then Worrall went close.
United were soon back on the attack. Sharp's shot was blocked after Baxter laid off Campbell-Ryce's cross and the woodwork was rattled for a third time on 87 minutes following Sharp's snap-shot, which beat Bentley but struck a post.
Five minutes of added time gave the fans hope but Southend kept United at bay and held on for a point.
Blades: Long, Freeman, Harris, Basham, Coutts (J Wallace 84), Sharp, Baxter, Collins, Campbell-Ryce, Adams, Hammond.
Unused: Howard, Done, Scougall, Sammon, McEveley, McGahey.
Southend: Bentley, White, Coker, Thompson, Worrall, Mooney (Pigott 64), Payne (Timlin 75), Atkinson, Hurst (Weston 68), Leonard, Barrett.
Unused: Prosser, Bolger, Smith, O'Neill.