Goals either side of the interval saw Bradford City suffer a 2-0 defeat at the hands of early-season pacesetters Barnsley.
In a fast start to proceedings, the Bantams conceded early but rallied going into half-time, as Michael Collins' men battled to level matters.
Despite going close shortly after the visitors' opening goal, City trailed 1-0 at the break.
But the home side, backed by a near 19,000 crowd at the Northern Commercials Stadium, had chances to equalise during the opening stages of the second period.
Against the run of play, however, on 69 minutes, City's Yorkshire rivals doubled their advantage and held firm to seal a second-successive victory.
Sean Scannell won an early corner for the Bantams, after breaking down the left wing.
But Barnsley cleared the danger and hit the front courtesy of a Tom Bradshaw header – on seven minutes.
This came after the away side threatened, with Bantams man of the match Anthony O'Connor clearing a Kieffer Moore shot off the line.
Inside 90 seconds, City went close at the other end. Hope Akpan fired a fantastic cross across the six-yard box and Scannell went within a whisker of getting on the end of it.
O'Connor was booked just past the half-hour mark for a late challenge on Barnsley's Bradshaw, who was downed just outside the area.
Kelvin Mellor denied the visitors a clear scoring opportunity on 49 minutes.
Bradford responded with jinking, dangerous runs from Sherwin Seedorf – who replaced Joe Riley on 46 minutes – and Scannell.
Nathaniel Knight-Percival almost got on the end of a Jack Payne free-kick as the hour mark passed.
And O'Connor went within inches of levelling matters when he headed a Payne corner over the bar.
Despite a period of dominance from the hosts, George Moncur drilled a shot towards the City goal and the ball, after a deflection, rolled into the path of fellow Barnsley substitute Victor Adeboyejo – who finished neatly in the bottom left corner.
George Miller took Scannell's place on 77 minutes but was unable to enjoy any clear chances.
The South Yorkshire outfit upped the ante during the closing stages.
And despite having two men booked for fouls, in Daniel Pinillos and Dimitri Cavere, Barnsley finished the stronger.
After seven minutes of extra-time, the away side confirmed their 2-0 triumph.
CITY: O'Donnell, Riley (Seedorf 46'), Chicksen, O'Connor, Scannell (Miller 77'), Doyle, Payne, Mellor, Akpan, Knight-Percival (Robinson 70'), Wright. Unused Subs: Wilson, McGowan, Bruenker, Hudson.
BARNSLEY: Davies, Dougall, Pinnock, Lindsay, Bradshaw, Cavere, Moore (Adeboyejo 67'), Potts (Isgrove 89'), Pinillos, Thiam (Moncur 67'), Mowatt. Unused Subs: McGeehan, Walton, Jackson, Williams.