Sunderland AFC 0 Sheffield Wednesday 2: Cats out of Carabao Cup after Alim Ozturk howler
Sunderland's League Cup hopes ended at the first hurdle after Championship side Sheffield Wednesday ran out 2-0 winners.
Sunderland dominated the early stages, impressing with their slick style of football, but a howler from summer signing Alim Ozturk allowed Marco Matias to prod the ball past Jon McLaughlin for the opening goal.
The Owls added a second with ten minutes remaining, ex-Middlesbrough winger Adam Reach nodding home at the near post.
A crowd of just 13,890 watched the first round of the Carabao Cup unfold at the Stadium of Light.
Sunderland made six changes to the team that drew with Luton Town, with Lee Cattermole handed his first start of the campaign.
Denver Hume and Elliot Embleton made their full debuts, with Ozturk partnering Jack Baldwin in central defence. Reece James made his first start after injury.
Luke O'Nien was recalled in midfield, with Chris Maguire leading the line with Josh Maja rested ahead of Sunday's game against Scunthorpe United.
Sheff Wed made seven changes for the Stadium of Light first round tie.
Sunderland dominated the opening stages of the game, their slick passing impressing, with Chris Maguire and George Honeyman linking up well up front.
Ross had gone with a fluid 4-4-2 system, with left-footed Hume at right back.
There were no clear cut chances until the 20th minute, Hume with a defence-splitting pass to Embleton.
The England youth international, who looked offside, on his weaker foot dragged his effort well wide with a poor effort.
And then almost immediately, Sunderland stopper Jon McLaughlin produced a smart, low save to deny Matias.
Ross would have been impressed with his players' performance but they fell behind against the run of play thanks to a howler from Ozturk.
A long Joe Wildsmith ball wasn't dealt with, Fletcher winning the flick on.
It should have been comfortable for Ozturk to deal with and clear his lines but he got his feet muddled up and Matias nicked the ball off him and slotted past McLaughlin.
Late on Luke O'Nien saw an effort deflected wide for a corner.
HT: Sunderland 0 Sheff Wed 1
Sunderland started the second half brightly. Honeyman saw a goalbound volley cleared for a corner by the head of Owls defender Frederik Nielsen.
Ozturk headed over soon after, failing to make up for his earlier error.
There were few and far chances in the second half, McLaughlin doing well to deny Reach with his feet after rushing out to meet him.
Ross made two positive changes with Lynden Gooch and then Josh Maja coming on for the hosts, Cattermole went off to applause when he departed for the 19-year-old striker.
Sunderland were denied a penalty midway through the second half, Gooch's cross hit Matias on the hand but the referee gave a corner.
Skipper Honeyman then saw his effort go high and wide after doing well to create the space in the first place on the edge of the area.
With 10 minutes remaining, Sheffield Wednesday extended their lead.
Barry Bannan swung over an inviting cross from the right and Reach glanced a near-post header in to the far corner of the net. He got in front of Hume to nod home.
Sheff Wed will now Wolves in the second round of the competition.
FT: Sunderland 0 Sheff Wed 2
SAFC: McLaughlin, James, Baldwin, Ozturk, Hume, O'Nien, Power, Cattermole (Maja, 66), Honeyman, Embleton (Gooch, 61), Maguire.
Subs Not Used: Ruiter, Robson, Molyneux, Mumba, Taylor.
Booked: Honeyman (32), O'Nien (59)
Sheff Wed: Wildsmith; Nielsen, Lees, van Aken (Penney, 63); Palmer, Bannan, Hunt (Kirby, 45), Boyd; Matias, Reach, Fletcher.
Subs Not Used: Dawson, Jones, Nuhiu, O'Grady, Lee, Penney.
Goalss: Matias (29), Reach (80).
Referee: Ben Toner (Lancashire)