Mario Balotelli scored both goals for City, but was sent off and will miss the clash with rivals Manchester United on Wednesday.
“I think we played a fantastic game. The guys were fantastic in this game, played football,” Mancini told Sky Sports.
“We scored two goals and we are happy for the guys and for the supporters because they were fantastic today.”
“For me, it was absolutely not a red card,” said Mancini of Balotelli’s dismissal.
“But the guys on the pitch played 200 percent,” he said, believing his team did well to limit the Baggies’ opportunities throughout the game.
“I think that today the guys defended very well and played football very well.”