A second-half goal from Max Watters proved enough for Barnsley to beat South Yorkshire neighbours Sheffield United 1-0 and reach the third round of the Carabao Cup.
Watters made the decisive breakthrough for the League One side in the 53rd minute at Oakwell, getting on the end of a move involving Barry Cotter and Phillips.
Sai Sachdev made his first start in a young Blades line-up and there was a full debut for Jesurun Rak-Sakyi, signed on loan from Crystal Palace.
The home side had a good chance towards the end of the first half when Watters laid the ball off to Adam Phillips, whose effort from 20 yards out was saved by Adam Davies.
After Watters had opened the scoring, Luca Connell put a free-kick wide as the hosts went in search of a second goal.
Cotter then fired in a shot from outside the area which took a deflection wide.
The Championship visitors made a triple change just after the hour-mark with Andre Brooks, Tyrese Campbell and Auston Trusty replacing Rak-Sakyi, Owen Hampson and Rhys Norrington-Davies.
Further changes followed with 17 minutes remaining, as Blades boss Chris Wilder sent on Gus Hamer and Harrison Burrows in place of Rhian Brewster and Sam McCallum.
Goalkeeper Gaga Slonina came to Barnsley’s rescue late on with a fine reflex save to touch Campbell’s close-range effort onto a post and ensure a happy night for the home supporters.
