Sam Winnall’s last-minute equaliser at Oakwell denied Aston Villa their second Championship win as Barnsley continued their good start to the season.
Jordan Ayew had given Villa the lead, picking up the ball inside the Tykes box before cutting inside and finding the bottom corner.
Jack Grealish, who missed Villa’s game against Newcastle after being suspended by the club, played 90 minutes.
But Winnall headed in Cole Kpekawa’s corner to deny the visitors victory.
Jonathan Kodija consistently tested Adam Davies in the first half, but the hosts’ keeper made a string of good saves.
Ayew’s first league goal of the season gave Villa a deserved lead just past the hour mark, as Roberto di Matteo’s side dominated against newly promoted Barnsley.
However, after Kpekawa’s blocked shot earned Barnsley a corner with a minute of play remaining, Winnall glanced the ball past Pierluigi Gollini.
Villa’s failure to kill off the match means they have not won a league game since they beat Rotherham on 13 August, and have drawn their last five leaving them 17th in the table.
Barnsley slip to 10th, but are just two points off Brighton in third.