The cup loss came against Bradford League big boys Woodlands despite posting what looked a decent 197-7 score from their 40 overs.
Joe Billings hit two sixes and nine fours in a 67-ball knock of 67 while Matty Taylor weighed in with 33no and Kieran Donnachie 27, but Woodlands breezed past the first innings score, losing only one wicket as openers Sam Frankland (88) and Tim Jackson (84no) led the way.
A day earlier Thornes were involved in a tight league game, but made it five wins out of five to open up an eight-point gap at the top of the table.
A fine effort in the field seemed to have set up a routine win when Cawthorne were dismissed for 92 after all of their top four were out for ducks. Taylor (4-22) led the attack well with two wickets each for Imran Mahboob and Brad Green.
But Thornes batsmen also struggled as they were reduced to 25-6 before Jawad Akhtar came to the rescue with an unbeaten 35. Mahboob (18) joined him for a crucial 44-run stand and Wakefield got home with just one wicket to spare.
Batting first, they made 180 after the innings fell away somewhat following a good start given by Jonathan Scott (63), Joe Cuthbertson (40) and Joshua Hen-Boisen (20).
But in reply Coal Aston were dismissed for 139 as Adam Nasar (5-23) led the Thornes attack and there were two wickets each for Hen-Boisen and Rob Stephenson.