It was Barnsley's first victory in 12 visits to Doncaster since 1967 and provided them with a quickfire double, after beating Rovers 4-1 with ten men at Oakwell three weeks ago.
Rovers were without key midfield men Richie Wellens and Brian Stock but forced the pace at the start.
Jason Price hit a low 20-yard shot inches wide in the tenth minute following good work by Mark Wilson and Lewis Guy to create the opportunity.
Macken had seen a left-foot snap shot saved moments earlier, but it was Doncaster who moved the ball about to greater effect in the opening stages.
Price hit another lot shot at the keeper in the 20th minute and James Coppinger cleverly turned his marker before firing just wide ten minutes later.
But Barnsley came more and more into the game with speedy winger Jamal Campbell-Ryce a constant threat.
Barnsley had not scored in seven games away from home since the opening match of the season, but they ended their goal famine helped by Rovers poor defending in the 43rd minute.
Sam Hird headed the ball straight to Martin Devaney, who linked with Anderson Da Silva to set up an easy tap-in for Macken from close range.
Rovers tried to battle back in the second half but their finishing failed to match their approach work.
Price volleyed wildly wide following a corner in the 60th minute and somehow managed to squander a golden opportunity eight minutes from time, after Paul Heffernan had set him up from point-blank range.
Barnsley hung on in the closing stages as Rovers efforts were in vain and the result made in ten successive games without a win for the struggling home side, who were dumped to the bottom of the table.