Oakwell boss Simon Davey was hoping to celebrate signing a new four-year deal with Barnsley's fifth home win in a row.
But instead his side ran out of ideas against Warnock's stubborn, well-drilled outfit who are slowly clawing their way up the table.
With chances at a premium both sides were wasteful in front of goal and a goalless stalemate always looked a possibility.
Palace on the break were close to claim an early lead when James Scowcroft's measured ball from the right skidded through for Clinton Morrison, but his sidefooted shot hit Lewin Nyatanga and gave the home side a let-off.
And when the home side failed to clear Morrison was close again when he flicked the ball cleverly past Dennis Souza and struck a crisp shot from 12 yards, but German keeper Heinz Muller turned it over with a super save.
Clint Hill might have done better with his glancing header after a Matt Lawrence cross but was wide of the target.
Barnsley keeper Muller failed to hold onto a stinging 25-yard free-kick from Ben Watson but Souza tidied up on the wet surface.
Barnsley, with four home wins in a row, struggled to carve out chances against Warnock's stubborn Palace side who were anxious to stretch their seven-match unbeaten run.
Palace keeper Julian Speroni had to be alert after a dangerous cross from Brian Howard and his brave block denied striker Istvan Ferenczi after impressive work by Jamal Campbell-Ryce.
Brazilian midfielder Anderson de Silva produced a 20-yard shot but it was wide of the post and failed to trouble Speroni.
De Silva was in the danger area again to produce another well-struck shot, but Mark Hudson hurled his body in to block the effort.
The Palace keeper though did well two minutes into the second half when Campbell-Ryce whipped in a right-sided cross that was dropping into the net, but Speroni stretched to turn it over the bar.
But Morrison should have done better for Palace soon afterwards when the ball broke for him off Scowcroft, but Morrison's angled shot was easy for Muller.