Cawthorne won at home to leaders Wakefield Thornes.
Liam Wiles smashed 162 off 134 with 23 fours and six sixes in Cawthorne’s 272 for eight. Syed Hassan and Mustafa Shinwari took three wickets each as the hosts were all out for 227.
Barnsley dropped into the relegation zone after a seventh successive defeat.
They were beaten at home to second-placed Cleethorpes by nine wickets, after collapsing from 130 to five to 146 all out.
They are now second-bottom, four points from safety with four games left starting against third-bottom Wickersley on Saturday.
