Manchester United loan signing Fraizer Campbell scored twice on his home debut to end Barnsley's seven-match unbeaten run at a bitterly cold KC Stadium.
Within seven minutes, Campbell had collected a Dean Windass pass to open the scoring and he followed up 11 minutes later, showing impressive pace.
Hull dominated - even with Jay-Jay Okocha and Henrik Pedersen injured - and deserved Dean Marney's late third.
After Jamal Campbell-Ryce's crafty chip was deflected, Barnsley slumped.
Hull boss Phil Brown:
"The chances have been coming in recent games and we have not taken them - but we did here.
"People will talk about Fraizer but I felt Dean Windass led the line like the old warhorse he is.
"It was a good performance all round and the most pleasing thing was probably the clean sheet - we deserved the win."
Barnsley manager Simon Davey:
"We wanted to keep our unbeaten run going but we lost the game after 25 minutes. Hopefully that's a reality check and we can kick on.
"I'm not going to criticise anyone too much - I'm just going to put it down to a bad day at the office.
"We've lost once in eight games so we now need to prepare for Saturday's game at Leicester."
Hull: Myhill, Ricketts, Turner, Brown, Delaney, Garcia, Marney, Livermore, Hughes, Windass (McPhee 75), Campbell (Featherstone 87).
Subs Not Used: Duke, Dawson, Elliott.
Goals: Campbell 7, 18, Marney 90.
Barnsley: Muller, Werling, Nyatanga, Foster (Christensen 68), Souza, Campbell-Ryce (Ricketts 81), Howard, McCann (Devaney 61), De Silva, Mostto, Odejayi.
Subs Not Used: Colgan, Kozluk.
Booked: Souza, De Silva.
Ref: Andy D'Urso (Essex).