Craig Davies struck in either half as Barnsley coasted to a comfortable Championship win over rock-bottom South Yorkshire rivals Doncaster.
Striker Davies made it four goals in as many games by steering in the 30th-minute opener and then volleying home Matty Done's cross on 64 minutes.
Barnsley were dominant throughout but debutant Doncaster keeper Carl Ikeme prevented a wider margin.
Rovers finished with 10 men after Adam Lockwood was shown a straight red card.
Doncaster manager Dean Saunders has now lost five of his 10 matches in charge since replacing Sean O'Driscoll in September.
Goalkeeper Ikeme made his first appearance after signing on loan from Wolves last week and made a string of top-class saves as Barnsley overran their visitors.
But he was powerless to stop Davies's opener which gave the home side a deserved half-time lead.
Keeper Luke Steele punted forward and Davies pounced on the bouncing ball in the Rovers penalty area to coolly convert from 12 yards.
Barnsley picked up where they left off at the start of the second half and doubled their lead when winger Done wriggled clear of two defenders before supplying the perfect cross for Davies.
And it got worse for Doncaster as Lockwood, a first-half replacement for Shelton Martis, was shown a straight red card following his clumsy challenge on Stephen Foster.