Sunderland boss Gus Poyet admitted that Wes Brown's early red card in the 2-0 defeat to Hull City completely changed the game.
After just four minutes the defender hacked down Shane Long who was bearing down on goal and referee Michael Jones had no hesitation in dismissing Brown.
Poyet was forced to reshuffle his pack, sacrificing striker Fabio Borini for defender Santiago Vergini, but goals from Shane Long and Nikica Jelavic either side of half-time secured the three points for the visitors.
The result leaves Sunderland just one point above the bottom three and Poyet is keen to ensure that old habits do not return for his side who had been on an impressive run of form.
"We've been very good in the last month-and-a-half," he told Sky Sports.
"Previously to that there was always something happening - a mistake, a deflected shot, a sending-off or whatever and today we went back to those times.
"It's difficult to analyse as it was a difficult game for us after five minutes."
Speaking of the sending-off, Poyet said: "It changed the game completely. We tried to reorganise the team and for a few moments it looked as though we were still in the game at 1-0.
"We started taking a few risks and of course the second goal killed the game.
"It's difficult to analyse. We were ready in a great position and a situation to play a good game of football and after five minutes everything changed."