Pep Guardiola lauded Bayern Munich's work-rate for following an extra-time victory over Juventus in the Champions League on Wednesday with a 1-0 win against Cologne on Saturday.
Bayern came back from two goals down to force an additional 30 minutes against Juve, before strikes from Thiago Alcantara and Kingsley Coman booked their place in the quarter-finals.
Having expended so much energy in the match at the Allianz Arena, Guardiola admitted they found things tough against Peter Stoger's side.
But Bayern held on after Robert Lewandowski opened the scoring inside 10 minutes, pleasing the Spaniard.
"Huge compliments to the players. After 120 minutes and an emotional game against Juventus, it was very difficult to come here two-and-a-half days later," said Guardiola.
"We did well in the first 30 minutes, with our goal and many good balls from the byline. Our start to the second half was also good, but in the last 25 minutes Peter brought another attacker on and they played many long passes.
"They were very dangerous, also in counter-attacks. But all in all we controlled the game. It is one more victory for us.
"I realised how difficult it is to defend our title in the Bundesliga. We must fight until the last match, but it's another win that put us in front."
Bayern now hold an eight-point lead over Borussia Dortmund, who take on Augsburg on Sunday, and Lewandowski felt they did well to hold on for the triumph.
"When you're only 1-0 up, it's always dangerous. It's important that we have the three points," he said.