Leading scorer Pitman wasted a gilt-edge chance to open the scoring when he headed wide from six yards after seven minutes and missed with an angled strike from the edge of the area shortly afterwards.
The Blades had been chasing victory with substitute Marcus Bent guilty of missing a gilt-edged chance from Bjorn Helge Riise's corner on the edge of the six-yard box while Joe Mattock lashed a 20-yard volley wide.