Wycombe boss Matt Bloomfield blamed his side’s ill-discipline for their 4-2 loss to promotion-chasers Barnsley.
The Chairboys twice let a lead slip before substitute David Wheeler was sent off as the Reds completed a resounding comeback.
Dale Taylor and Kieran Sadlier twice put Wycombe ahead, only for Sam Cosgrove and Donovan Pines to respond each time before Corey O’Keeffe and Conor Grant secured the victory.
“Where was it lost? Slight lack of discipline, I think,” Bloomfield said. “There were a couple of soft goals that were entirely preventable from our side, so that feeds into it, and obviously the sending-off doesn’t help.
“I still fancied us at 3-2 down, but obviously with 10 men it’s tough.
“A few things contributed, maybe a slight bit of fatigue crept in with some of our decision-making at times defensively.
“I thought we started the game extremely well. For 30-35 minutes to play like we did against a team that’s looking to try and get up automatically, we have to be pleased with that, but we’re not pleased because we want to win the game.”
Taylor’s 16th-minute opener was cancelled out by an equaliser in first-half stoppage time from Cosgrove, who netted the rebound from a Luca Connell free-kick.
Sadlier then tapped home after good build-up play from Garath McCleary to restore the hosts’ lead, but only for four minutes.
Pines bundled the ball home before O’Keeffe put Barnsley into the lead for the first time with 65 minutes gone.
Wheeler saw red less than a minute after coming on for a heavy tackle on O’Keeffe and the Tykes made certain of their win with a thumping effort from Grant.
Barnsley boss Neill Collins said: “The resilience they’ve shown after going behind and then going behind again, to come back was fantastic.
“The quality of our play when we put it together caused Wycombe real problems. We created some really good moments and the quality of a couple of our goals was excellent.
“So I think overall, coming away from home against a team that’s made it really difficult for teams at home recently is all positive.
“I think we were the victims of our downfall with respect to the two goals we gave away and then when we did go 4-2 in the lead we contrived to give up two or three chances just from poor choices.
“But in the end we regrouped and saw it out pretty comfortably. There’s more positives than negatives of course.”