Goals by Jack Lester for the visitors and Rotherham's Andy Monkhouse ensured the spoils were shared in a match where effort was in abundance but quality was at a premium.
In a game neither side dared to lose the Millers defied their poor recent form as they refused to let their high-flying visitors settle into any kind of rhythm and created the better chances.
The Millers signalled their attacking intentions from the outset and Blades keeper Paddy Kenny had to get down quickly to gather an Andy Monkhouse volley on the line in the eighth minute.
Dries Bousatta spurned a chance to put the visitors ahead when he skied a first-time shot despite having plenty of time to control the ball while unmarked at the edge of the 18-yard box.
Proctor's pace and persistence were causing all kinds of trouble for the Blades and the home crowd clamoured for a penalty claiming he had been pushed in the back but the referee was unswayed.
Lester had a shot blocked in the 42nd minute as the game swung from end to end but they had created very little of note.
A minute later Kenny tipped over a close-range strike destined for the net by Proctor after he had controlled the ball, turned and shot from eight yards as the Millers finished the half well on top.
But it was the visitors who went ahead shortly after the restart.
Chris Swailes was adjudged to have brought down Andy Gray after he twisted and turned in the area and Lester buried the spot-kick for his second goal in two games.
But the Millers deservedly levelled when Monkhouse scored his third goal of the season from close range after great work down the right by Martin Butler in the 52nd minute.
Butler sent a header just past the upright with Kenny beaten before a speculative Peter Ndlovu shot from outside the area was a whisker wide for the Blades.
Rotherham could have scored two in a minute with Proctor at the centre of the action.
Kenny was United's saviour when he saved from Butler who was unmarked in the box after a Proctor pass dissected the Blades defence.
Proctor himself then fired wide following a cross from Scott Minto's cross with the goalkeeper beaten.
But it was the visitors who almost snatched victory in injury time when Michael Tonge's thunderous shot from the left side of the area was beaten out by keeper Mike Pollitt.
The game finished at the same frenetic pace it had started but the sides had to settle for a point apiece after playing each other to a standstill.