Barnsley manager Mark Robins was left feeling "flat" after the 1-1 draw against Derby.
The Tykes needed in-form winger Adam Hammill to rescue a point from the npower Championship fixture at Oakwell.
Hammill was tormentor-in-chief when Barnsley defeated Leeds 5-2 in midweek and the former Liverpool trainee denied Derby their first win since the opening day by cancelling out Dean Leacock's first-half opener.
Robins said: "We set off okay and passed the ball around well at times. It was an elementary mistake to make that put us behind in the game.
"It feels like we've lost the game because of Tuesday night's performance.
"Here the confidence should have been high and it was in certain areas - the back four did well. We were strong to come back after losing a goal and we could have done a lot better. It's a disappointment. In the dressing room it's a flat feeling due to the fact we played so well on Tuesday and the players agree we should have done a lot better.