A blast from Oldham oldboy Jose Baxter earned the Blades a point on Boxing Day.
Trailing to a Jonson Clarke-Harris first half effort, Baxter levelled with a thunderbolt free-kick early in the second period.
Baxter also hit a post in injury-time but the Blades had to settle for a point and a seventh game without defeat.
Following an impressive pre-Christmas performance at Stevenage, boss Clough named an unchanged squad - starting XI and substitutes - for the visit of the Latics. United's team included former Oldham players Baxter and Porter, whilst at right-back for the visitors was ex Blades youngster, Brown.
Despite seeing a lot of the ball in the opening five minutes, the Blades made a disastrous start. Miller lost possession, gifting Oldham the opportunity to score with their first attack - which they duly took. Rooney's cross from the right saw CLARKE-HARRIS nip in front of his marker to nod beyond Long.
Further disruption for Clough's plans saw White limp off moments later, replaced by Murphy, whilst a few nervous moments in possession did little to lift the mood of the crowd. Oldham could have had a second on 20 minutes but when Clarke-Harris put away Long's parry from Smith's shot he was in an offside position.
The Blades struggled to find their rhythm in the first half, despite Hill and Murphy seeing plenty of possession down the left flank. The only home chance of note arrived on 44 minutes when a quick break resulted in McMahon's cross for Porter but the striker could not find the target with his header.
United kicked off the second period by forcing a save out of goalkeeper Oxley, although referee Brown penalised Maguire for a foul, whilst Oldham hit back with a 30-yard free-kick from Smith, which was expertly saved and held by Long.
The Blades, however, levelled with another free-kick soon after. Defender Kusunga may not have thought that his foul on Porter 30+ yards from goal was in a dangerous position but BAXTER lashed home before Oxley could move and although his celebration was mooted out of respect for the visitors, the Unitedites in the stands enjoyed the moment.
As well as bringing United level, the goal gave Clough's side momentum and Oldham were forced to soak up a spell of pressure. Collins headed wide a Baxter corner and then a left-footed McMahon shot popped out of Oxley's grasp but Porter was unable to take advantage.
McGinn picked up the game's first yellow card for a foul on Petrasso and from the resulting free-kick Long spilled but Hill cleared up in a crowded penalty area.
As the game entered the final ten minutes, Oldham went close on the break but Long saved from Rooney and then the Blades made a double change with Flynn and Taylor taking over from Murphy and Miller.
Four minutes of injury-time saw the Blades on the offensive and Baxter came within inches of adding a second when, after cutting in from the right, his effort was deflected onto a post. From the resulting corner, Doyle delivered back into the danger area but efforts from Porter and Flynn were kicked away.
However, the elusive winner was not forthcoming and Clough had to settle for another point as the Blades continue to ease away from the relegation area.
Blades: Long, White (Murphy 9, Flynn 85), Maguire, Hill, Doyle, Port corner, Doyle ack in er, Baxter, Miller (Taylor 85), McGinn, Collins, McMahon.
Unused: Howard, Coady, Brandy, Lappin.
Oldham: Oxley, Brown, Grounds, Kusunga, Tarkowski, Smith, Rooney, Mellor, Clarke-Harris, Lanzoni, Petrasso (Millar 87).
Unused: Schmeltz, Winchester, Byrne, Rodgers, Plummer, Rachubka.