Sunderland manager Steve Bruce hit out at Lee Cattermole and David Meyler after they were both sent off in the 1-1 draw at rock-bottom Portsmouth.
The Black Cats looked to be on course for a morale-boosting win at Fratton Park, but after being reduced to nine men, Bruce's side conceded a last-minute equaliser.
"Sometimes it's difficult to come out and say anything. We've lost two points because of our own stupidity," Bruce told the club's official website.
"We've gained the ascendancy and then handed it right back to Portsmouth by doing two stupid things. I just can't defend it, it's ridiculous.
"I can't defend Lee Cattermole and I can't defend David Meyler. They have cost us three valuable points.
"It's so disappointing because a win would have given everyone a huge lift. We were in complete control and just threw it away.
"We must stop the stupidity because that is what's cost us. That will be dealt with and we will learn from it."