Atletico Madrid coach Diego Simeone praised his side after they secured a seventh consecutive victory on Tuesday.
Luciano Vietto's goal on 55 minutes proved to be vital as Atletico picked up a 2-1 win away to Benfica on the final matchday of the Champions League group stages.
The three points mean Simeone's men finished top of Group C, above their Portuguese opponents.
The win stretched Atletico's unbeaten run to 13 games - with their last defeat coming against Benfica at the end of September.
"The lads have been making an extraordinary effort," Simeone said. "It's not easy to win and win, to follow this dynamic and keep winning.
"It was an important game against an opponent who plays very well. We secured an important victory for what follows.
"As we said before winning, nothing was guaranteed. We had to do something and we did."
The 45-year-old also heaped praise on Atletico's two goalscorers - Saul Niguez and Vietto.
"We knew that we had depth down the left," Simeone said. "Griezmann enabled Vietto and Saul to have that space. Saul's goal broke the monotony of the game that was there at the time.
"Vietto is a player who plays well down between the lines, assists and is growing. He has a lot more confidence and plays better in the structure of the team.
"Many times we tell him to go to the first post and today he did it and scored."
