Swansea boss Russell Martin was fuming after his Championship side squandered a two-goal lead at half-time and lost 5-3 on penalties against League One side Oxford at the Kassam Stadium.
Jay Fulton and Liam Cullen put the Swans two up in 25 minutes and they had other good opportunities before an error from keeper Steven Benda on 72 minutes gave Oxford hope.
His casual clearance was charged down by Alex Gorrin, the ball ricocheting into the goal.
Then, substitute Cameron Brannagan fired home a stoppage-time equaliser from a free-kick that deflected off the wall.
Martin said: “For 65 minutes we were so good, the fans were signing and some of our football was outstanding.
“Then we make changes, some forced and some not – but the subs should not change the game as much as they did.
“The first goal we conceded was pathetic, and then you’re in a war. But how it descended into that, I don’t know.
“Yes we had a young side out at the end but it’s up to the experienced players to help us out.
“It was sink or swim time for some of them and unfortunately a few of them sank. I’m really angry and frustrated. We should have been out of sight. I am angry, and the boys should be angry.
“Tonight we were so good for 65 minutes – how it can go so completely the other way? Our game management in the last 10 minutes was terrible.”
It was Brannagan who smashed home Oxford’s winning spot kick after debutant goalkeeper Eddie McGinty made up for his own error earlier in the match – handling outside his box which led to Swansea’s opener – by saving Matty Sorinola’s spot kick in the shoot-out.
Oxford boss Karl Robinson said: “It was a great night for us. The team we began with had had so few starts, and then we made a silly error which was punished, and we kept getting picked off in certain areas.
“But I said to my coaching staff at the end – ‘this free kick will go in, and McGinty will make the winning save in the penalties’, and that’s what happened.
“We have that never-say-die attitude here, it’s in the players’ DNA. The heaviest responsibility our players have here is wearing the shirt, fighting and doing everything possible when you wear that shirt.”
