The Reds held Boro to a goal-less first half but 3 goals in the opening 12 minutes of the second half through Yakubu (2) and Maccarone showed their true class.
New signing Michael McIndoe managed to pull one back for The Reds after 77minutes.
Barnsley's next pre-season friendly is at Halifax Town this Saturday.
Ticket News: http://www.barnsley-mad.co.uk/news/loadnews.asp?cid=TMNW&id=288095.
Meanwhile Reds boss Andy Ritchie has claimed that The Reds are set to bring another goal-keeper in on trial tomorrow as they look to replace Scott Flinders. He will play some part at Halifax.