An Istvan Ferenczi tap-in and a Heinz Muller penalty save from Andy Keogh earned Barnsley a fourth successive home win.
The hosts grabbed their goal in the 49th minute, thanks to a bizarre attempt to clear by Karl Henry which landed at the feet of Ferenczi.
Andy Keogh's penalty followed just after when substitute Stephen Elliott was fouled by Lewin Nyatanga
But the highly-rated German goalkeeper Muller was equal to Keogh's shot.
Barnsley assistant boss Ryan Kidd:
"It was a good performance from us tonight and we've got to take that forward. We overpowered Wolves.
"We passed the ball well and the work-rate was amazing considering the amount of matches we've played.
"The lads worked their socks off. They know they must keep doing that because there's pressure on places in the team. It's a good place to be at the moment."
Wolves manager Mick McCarthy
"We were hopeless, I can't find a better adjective for that performance.
"I am not going to take anything away from Barnsley, they were very competitive and deserved their win.
"That was us three or four weeks ago, that level of performance (by Barnsley) and we have to get back to it."
Barnsley: Muller, Foster, Souza, Nyatanga, Werling, Campbell-Ryce, De Silva, Howard, Devaney (Togwell 69), Macken (Mostto 88), Ferenczi (Christensen 90).
Subs Not Used: Reid, McCann.
Goals: Ferenczi 47.
Wolverhampton: Hennessey, Foley, Darren Ward, Collins, Gray, Jarvis (Elliott 46), Olofinjana, Potter (Gibson 56), Henry, Stephen Ward (Eastwood 66), Keogh.
Subs Not Used: Edwards, Ikeme.
Booked: Potter, Gibson, Henry.
Ref: Graham Salisbury (Lancashire).