BORO: Jones, Naughton (Hoyte 90), McManus, Pogatetz,Grounds, Flood, O'Neil, Robson, Franks, Killen (Miller 68), McDonald. Subs Not Used: Steele, Lita, McMahon, Bennett, Luke Williams.
BARNSLEY: Steele, Trippier (Hume 77), Foster, Moore, Dickinson, Teixeira, Doyle, Colace, Hallfredsson (Hammill 58), Andy Gray, De Silva (Rodriguez 46). Subs Not Used: Preece, Macken, Potter, Butterfield.
Att: 17,775
Only Reading had won fewer home games but Boro put in a wonderful first-half display, capped by goals from Chris Killen and Gary O'Neil, set the Teessiders on their way to three points and a step nearer the promotion play-off places.
Barnsley improved significantly after the interval and reduced their deficit through Hugo Colace's 65th-minute strike, and could possibly have stole a point before the final whistle.
Gordon Strachan rang the changes, bringing in former Celtic striker Scott McDonald for his first appearance for Middlesbrough after his high-profile transfer.
That meant Lee Miller dropping to the bench, while Emanuel Pogatetz replaced the injured David Wheater.
The visitors were the first to threaten, with Filipe Teixeira flicking a volley wide from Emil Hallfredsson's cross.
However, Boro soon got into their stride and McDonald saw a powerful angled drive superbly saved by Luke Steele in the eighth minute, the Barnsley goalkeeper sticking out his right boot to deflect the ball to safety.
The Teessiders went close again 10 minutes later. Killen was sent clear through on goal, but after lobbing the ball over Steele the forward saw his goalbound shot cleared off the line by Trippier.
Middlesbrough were eventually rewarded for their pressure in the 24th minute, Killen prodding home from close range after O'Neil's corner had been flicked on at the near post.
Barnsley saw appeals for a penalty waved away soon after when Colace's cross appeared to strike the arm of Pogatetz.
Darren Moore then headed wide from a Colace free-kick before Boro doubled their lead in the 34th minute.
Barry Robson picked out O'Neil with a delightful through ball and the former England Under-21 skipper composed himself before slotting past the advancing Steele.
O'Neil nearly added a third two minutes before the break, but Steele dived to his left to keep out the midfielder's low strike from the edge of the area.
Jay Rodriguez replaced Anderson de Silva at the start of the second half as the visitors switched to a 4-4-2 formation.
The change provided Barnsley with a greater attacking threat and they pulled back a deserved goal in the 65th minute.
Boro's defence failed to deal with a long throw from the left and Colace was on hand to drill home a low shot from the edge of the area.
Andy Gray had a golden chance to pull the Tykes level five minutes later, but headed tamely at Danny Coyne from Teixeira's cross.
McDonald then fired over for Middlesbrough following a swift counter-attack, before Rodriguez wasted Barnsley's final chance in the 90th minute as he headed wide from Nathan Doyle's cross.