Palace claimed a 2-0 win over Albion last time out thanks to second-half goals from Yannick Bolasie and Yohan Cabaye.
McArthur was delighted with the dominance the Eagles displayed throughout the 90 minutes, despite the fact they were held for 68 minutes by the Baggies, and he believes it was their best performance for some time.
"I felt we dominated the game from start to finish and it was one of our best performances," he told the Croydon Advertiser.
"You look at the performances last year against Manchester City [a 2-1 win at home] and Liverpool [a 3-1 win at Anfield], but for dominance, we felt so comfortable.
"Even at 0-0 at half-time we were very confident of winning. Not many times in the Premier League you'll dominate from the first whistle to the last.
"It was always going to be hard to break West Brom down but we talked about them before the game and we knew it might take until 70 minutes.
"The gaffer was on to us, telling us to remain calm and patient, and that we'd break through.
"You look throughout the whole team and it's hard to pick anyone out who played poorly.
"Everyone really stepped up, it was a great performance and an even better win."
Palace are currently third in the Premier League table, with 15 points from eight games, and they host West Ham in their next fixture after the international break.