Nathan Tyson grabbed a hat-trick as Rovers ended a run of five home games without a victory to extend the Iron’s miserable sequence to 10 away matches without a win.
Doncaster were given a helping hand when they snatched the lead in the 10th minute with Niall Canavan having the misfortune to head a free-kick from Kyle Bennett into his own net.
Tyson made it 2-0 when he headed home from close range after 33 minutes following a brilliant right-wing cross from Bennet.
Skipper Rob Jones added the third goal against his former club with a glancing header following a corner from Harry Forrester in first-half injury time.
Scunthorpe looked more determined at the start of the second half and pulled one back in the 53rd minute following a crazy goalmouth scramble.
A clearance from Jones bounced off Kevin van Veen then off the post before rebounding off Andy Butler and into the net for the most unfortunate of own goals.
Doncaster made sure of the points when Tyson converted penalties in the 74th and 79th minutes, conceded by Marcus Williams and Canavan respectively, before teenager Hakeeb Adelakun notched a second for the Iron with a free-kick in injury time.