Cardiff City lost top spot in the Championship as Doncaster secured their first league win of the season.
Adam Lockwood scored only Doncaster's third league goal of the season when he headed in Martin Wood's corner.
And striker James Hayter pounced to double the lead when Brian Stock's shot hit him and he curled the ball home.
Cardiff's best chances saw sub Kelvin Etuhu have a flick header cleared off the line and Michael Chopra fail to capitalise on a poor Rovers back-pass.
The hosts impressed and deserved their victory, but Cardiff's first defeat at Doncaster since 1951 was also their first defeat of this season.
Bluebirds boss Dave Jones was dealt a further blow as influential striker Jay Bothroyd was forced off injured in the opening 10 minutes.
Doncaster's first-half strikes shocked the Championship leaders who were chasing their fourth successive victory.
Although Chopra, Peter Whittingham and Etuhu, who replaced the injured Bothroyd, went close, Cardiff failed to score for the first time this season.
Cardiff City manager Dave Jones said:
Jones slams Cardiff work-rate
"Do I feel happy? No I don't. I don't think we turned up in the first 20 minutes and you can't afford to do that to any team at this level as we gave them a two-goal start.
"Going forward too many people didn't do enough and I have no problem with the result because fair play to Doncaster, they worked hard, stopped it and deserved the win.
"We didn't rise to the occasion until we were 2-0 down and it was too late as we were chasing the game.
"They scored from a cheap corner that we conceded then for the second goal, the lad hit a shot which was going well wide but it deflected off one of their players and because one of my players stayed in he was playing the lad offside and he scored.
"Defeats happen in football. Players' ability will always be there but if you don't put the work in - and some of them didn't put the work in - it won't always work out. That should be a wake-up call for us."
Doncaster Rovers manager Sean O'Driscoll said:
"We performed and created chances. In this division if you go two up you can close the game out and I thought we did that well.
"Losing Bothroyd was a blow for Dave but we coped well with Michael Chopra. He's on fire at the moment but we dealt with that.
"I thought our strikers did well and took their chances. We thought maybe Hayter was offside for the goal, but we got it.
"They did well. I think one of our Achilles' heels was that we don't finish chances. But the quality we are after we can't afford.
"We don't want to buying players who are no better than what we have got because that would just be wasting money. But something might happen before Tuesday.
"If we could bring someone in then we would. This was a good result but also a good performance."