Alan Pardew’s men – who remain two points behind the Blades and in 18th place - had taken the lead through a long-range effort from Talal El Karkouri on the hour.

However, they then sat back and invited pressure from the visitors, who levelled through Jon Stead with 20 minutes left.

Neither side could find a winner, and although they each gained ground on fellow strugglers Wigan – who lost at Liverpool – matches are fast running out to save their top-flight status.

The Valley had been baked in sunshine on a fine spring afternoon in south-east London.

The home faithful were rocking after an ABBA tribute band warmed them up for what was certainly a 'Winner Takes It All' encounter.

Charlton legend Derek ’Killer’ Hales called on the Red Army to find their voice as he rallied the crowd with a pitch-side walk-on just before kick-off.

With the atmosphere set, the opening exchanges were just as electric.

Winger Dennis Rommedahl was also pushed forwards down the right flank as Charlton started at full throttle.

The game was less than three minutes old before referee Alan Wiley had his yellow card out.

Keith Gillespie sent in a low cross from the right – and Luton Shelton dived through the six-yard box to try and knock the ball in with his hand, leaving the referee little option but to go for his pocket.

Both sides looked dangerous on the counter-attack.

After 13 minutes, Rommedahl – out of contract this summer – skipped away down the right and his low centre flashed across the six-yard box.

The flying Dane was soon clear again, this time chipping the ball up for Darren Ambrose, whose looping header dropped just wide.

England striker Darren Bent shot wide at the near post following a well-worked corner from Ambrose.

After 19 minutes, Blades keeper Paddy Kenny tipped over a curling 25-yard free-kick from El Karkouri.

Kenny was soon scrambling down to his right to push Thomas’ 25-yard drive behind.

The Charlton winger then conceded a free-kick in a dangerous position at the other end for a late sliding challenge on Nick Montgomery.

However, from just outside the ’D’ on the left, Tonge struck his shot straight into the wall.

United were now enjoying a decent spell of pressure. After 35 minutes, Gillespie forced a fine one-handed save from Scott Carson at the far post following Armstrong’s deep left-wing cross.

As half-time loomed, Charlton looked to play some football in the visitors’ half again. However, once more there was no telling pass to open up the Blades defence.

After a slow start to the second half, slowly Charlton came to life as the hour mark approached.

A chipped pass from Zheng Zhi almost found Jerome Thomas in the right side of the Blades penalty area.

Then out of nothing, Charlton took the lead. There looked to be little danger when Karkouri picked the ball up just inside the visitor’s half on 59 minutes.

The Moroccan defender strolled forwards and unleashed a 35-yard low drive, which took a slight deflection off the boot of Tonge and flew past Kenny low into the bottom right corner.

The relief was clear around The Valley – but Sheffield United immediately went on the attack. Stead flashed a header over the bar from a left-wing free-kick.

Charlton continued to sit back and invite pressure. United, though, failed to make the most of their possession – which included two free-kicks in dangerous positions around the 18-yard box.

However, the Blades were level on 70 minutes. Nick Montgomery fed Stead on the right side of the penalty area.

The former Sunderland and Blackburn striker took a touch before drilling an angled drive into the far corner.

With 15 minutes left, Charlton boss Alan Pardew sent on veteran striker Jimmy-Floyd Hasselbaink in an attempt to win the match, replacing Thomas and going to 4-4-2.

The Blades, though, always looked dangerous on the break. In the end, neither side could find a winner, despite five minutes of stoppage time.

The visitors will have gone away happier with the point, their fans chanting “we are staying up” at full-time – but the Blades will need a few more yet before they are home and dry.