The Ghanaian fetched the equalizer that helped the Spanish side to settle for a 1-1 draw at home against Qarabag from Azerbaijan.
"We lacked a bit of luck to score the second goal. We played a great game and now we cannot lower our arms," Partey said.
"We created many occasions. We have to keep fighting as a team.
"We all work to score goals every weekend. We have to continue without lowering our arms and fighting until the end," he added.
Atletico will face Roma at home on November 22 before travelling to Stamford Bridge to lock horns with Chelsea in the final game in December.