Paolo Di Canio did not know whether to laugh or cry after seeing Sunderland stage a dramatic fightback to book their place in the third round of the Capital One Cup.
The Black Cats were hurtling out of the competition at the hands of League One MK Dons when they finally slipped into top gear with just 12 minutes of normal time remaining to drag themselves back from 2-0 down to win 4-2.
Di Canio said: "It was very bad, but I know also it is easy to play badly in this game. Unfortunately, it happens even to the top clubs who play with the top players in this league.
"It's something that have thought for many years, why do top teams in the cup in England have to go out easily against League One and League Two sides? I don't understand.
"But I understand [now]. I was worried, and I was right, but I took something really good from the last 15 minutes, the ambition, the desire, the pride and the goals that we scored in style.
"I am very, very happy for 15 minutes; I am very, very angry for 75, so the balance is not very good."
Sunderland looked to be dead and buried after MK Dons took the game by the scruff of the neck and established a 2-0 lead within 55 minutes.
Neither Patrick Bamford's seventh-minute opener nor Izale McLeod's cool strike 10 minutes of the restart came against the run of play with the Black Cats distinctly second-best.
By that point, the cavalry had arrived in the shape of substitute Connor Wickham, although the visitors had negotiated their way to within 12 minutes of the final whistle before their defences were finally breached.
It was Jozy Altidore who sparked the fightback, running on to Wickham's through-ball to claim his first goal in English football, but it was the former Ipswich striker who broke MK Dons hearts with a quick-fire double inside the last four minutes with Adam Johnson completing the job in the sixth minute of stoppage time.