The Rams came into Saturday's game on the back of wins over Birmingham, Watford and Blackpool and there was no danger of it being anything other than another routine three points as Nigel Clough's men dominated in front of more than 23,000 at Pride Park.
Veteran Kevin Kilbane opened the scoring in the sixth minute when he headed home a corner and Steve Davies doubled the lead early in the second period with another header.
Ben Davies, who had created the first two goals, then deservedly got on the scoresheet when he struck from the edge of the area as the Rams outlined their promotion credentials.
For Doncaster in contrast it was a fourth straight defeat and they were made to pay for failing to make a period of first-half domination count.
Indeed, Rovers are without a Championship win since they won at Derby at the start of March, 16 games ago.
Having made such a positive start to the season, the confidence was flowing at Pride Park and it did not take long for Clough's side to grab the initiative as they went ahead in the sixth minute.
Ben Davies whipped in a corner from the right and Kilbane climbed highest and powered home a header to give his side the perfect start.
However, any thoughts of an easy afternoon were misplaced as Rovers came into the game and began to control it.
Keeping faith with their passing game, Sean O'Driscoll's men had a golden opportunity to level, but Giles Barnes, returning to Pride Park after he was sold to Fulham in 2009, blazed over from a great position after good work from Chris Brown.
Rovers continued on top, but were restricted to long-distance efforts and were unable to turn their pressure into rewards.
And they were made to pay just 20 seconds into the second half as Derby doubled their lead.
Ben Davies advanced down the left and earned his second assist by setting up Steve Davies to head home at the far post.
It gave the Rams some breathing space and Steve Davies headed over shortly after as they pushed for a third.
And it was not long coming as this time Ben Davies got in on the act, curling home a sweet effort from 20 yards in the 62nd minute.
Derby knew they had the points in the bag and took their foot off the gas, but Rovers were unable to capitalise on a comfortable afternoon for the hosts.