The Magpies were booed off the pitch after suffering a 3-0 defeat at the hands of their local rivals.
"The better team won, for sure," Pardew told BBC Sport. "We didn't look our usual selves. Maybe we were too hyped up for it.
"We gave the ball away and we struggled. Though we created chances, we didn't look like we had the conviction to score.
"We have to look at ourselves and make sure we are strong between now and the end of the season."
Pardew added: "We have lost a good player and have another who scores goals sitting out. We have to find another way to play, maybe a with a back-to-basics element to make sure the second half of the season mirrors the success of the first half.
"A lot of the play went through Yohan, so maybe we have to change our style. Sunderland were more controlled, had a better shape and they are things we can put right."
Sunderland have now won their last three matches against Newcastle.