The Blades began brightly and dominated the visitors early on, but failed to find the breakthrough and paid the price in the second half when Joe Willock fired home from a tight angle for what proved to be the winner.
Ollie Norwood was denied what would have been an eye-catching equaliser by a good save from Seny Dieng as United, who welcomed back Jayden Bogle from the start but suffered another injury concern when George Baldock limped off, saw their lead at the top of the Championship cut further.
Here’s how we rated United's players on a forgettable evening at Bramall Lane ...
1. Player ratings
Oliver McBurnie of Sheffield United reacts during his side's defeat to QPR (George Wood/Getty Images) Photo: George Wood
2. Wes Foderingham 5
Making his 50th appearance between the posts for the Blades, he was alert to push Chair's effort from a dangerous area behind but may feel he could have done better with Willock's opener as he squeezed the ball in at the near post after being afforded acres of space in the box. Did well to deny Dykes as he looked to double his side's lead Photo: Andrew Yates
3. George Baldock 5
Had a good chance to break the deadlock when Bogle's deep cross found him at the back post but he couldn't get enough purchase on his header, under pressure from his marker and it went begging. Went down with an injury issue late in the first half and didn't last long of the second before making way for Khadra Photo: Andrew Yates
4. Chris Basham 5
Tested Dieng early on with a well-struck volley on his left foot but couldn't do enough to stop Chair waltzing past him and testing Foderingham midway through the first half. Was limping in the second half and looked to struggle at times with the directness of Chair and Co. Photo: Andrew Yates