Doncaster were left to rue their ill discipline as they crashed to a 3-0 defeat at Sheffield Hallam and lost top spot in the EHL Conference North.
Oliver Ward and Joe Morrison were both dismissed during a niggly derby in which the Town Field men - chasing a league and cup double - failed to play with any sort of rhythm or cohesion.
Doncaster, without influential German Andre Otten, started slowly and allowed the hosts to press them back into their own half.
And the game hinged on two Sheffield goals midway through the first half which disrupted Doncaster’s flow even more.
The visitors should have pulled a goal back when a Tim Shelley short corner hit the defender on the line, Richard Thomas played the follow up off the same defender and Joe Morrison slotted home the rebound.
But the umpire had already blown for an offence and the subsequent short corner was pulled wide.
Sheffield’s Will Hearn saw yellow for a dangerous tackle but Doncaster failed to capitalise on the man advantage.
And after Ward and Morrison had been sin-binned a third Sheffield goal ended the game as a contest.
Durham University replaced Doncaster at the top of the table, courtesy of goal difference.
Barford Tigers are the visitors to Town Field on Sunday (2pm).
n Doncaster Ladies lost 3-2 at home to Sunderland and stay sixth in the table.
Abbie Grant and Kirstie Grace scored for Doncaster.