Sheffield United lost their unbeaten home record to strugglers Hartlepool United at Bramall Lane - and were leapfrogged by Tranmere Rovers as the new League One leaders, writes Robert Gledhill.
League One leaders Blades made three enforced changes against the bottom club.
Darryl Westlake and Marcus Williams came into defence for suspended Tony McMahon and Neil Collins (fractured cheekbone).
John Cofie replaced striker Shaun Miller, who is out for the season with a damaged knee.
The Blades 150th anniversary celebrations were cut short when Steve Howard headed Hartlepool into a fifth-minute lead.
Ryan France went close and Nick Blackman tested the goalkeeper before Scott Flinders spilled a 20-harder from Michael Doyle over his shoulder for the 31st-minute equaliser.
The half finished 1-1 leaving the Blades to prepare to attack the Kop end.
The Blades were stunned as former Owl Ritchie Humphreys drove Hartlepool back into the lead in the 54th minute.
Howard made it 3-1 when he headed home in the 72nd minute and there appeared no way back for the disappointing hosts.
Harry Maguire made the final score 3-2 in the fifth minute of stoppage time.