Gameiro set up Griezmann for a 2-0 lead and created another chance for his compatriot minutes later, before adding his own name to the score sheet as well when he converted a penalty in the second half in the first leg of their last-16 clash.
Atleti's win at the BayArena saw them take a major step toward the quarter-finals and Griezmann was quick to highlight Gameiro's role in their victory.
"Gameiro is brilliant, I get on really well with him," Griezmann told Canal+.
"He and Torres both scored and hopefully they can carry on that way.
"Gameiro has set me up seven times and I have given him three or four, we have a good understanding and the fact he is French also helps.
"We knew it was going to be a tough game. We wanted to win, we did that and the return leg will be difficult as tonight was.
"They pressured us and made life difficult, but the boss's changes helped us win the game. We have a big game to play now in front of our own fans."