Atletico Madrid coach Diego Simeone singled out Luis Suarez as the difference-maker for Bercelona following their 2-1 victory.
Barca edged Atletico in the top-of-the-table clash on Saturday to open a three-point lead at the La Liga summit.
Goals from Suarez and Lionel Messi before half-time powered the European champions to victory.
Simeone reserved praise for the Uruguayan, who is the leading scorer in Europe with 31 goals in 32 games.
"He is such an important player, he makes the difference. Without doubt his arrival has given Barcelona more penetration than they already had," Simeone told SkySports.
"He has different qualities to the rest. He is strong, a typical No 9 in the area, he is a very complete player and he has enriched Barcelona.
"I think he was already a very complete player at Liverpool and here he has been even better. Luis gives us a lot of things and all of them are positive."