Manchester City boss Manuel Pellegrini said his decision to prioritise the Champions League over the FA Cup was vindicated by the win at Dynamo Kiev.
"Having just 13 fit outfield players - it was a key decision to rest the team in the [FA Cup] game," said Pellegrini.
"It was important for the way we had to play this game with lots of intensity."
Pellegrini made 10 changes as he went with his strongest available line-up in Kiev.
Sergio Aguero, David Silva and Yaya Toure scored for City, while England keeper Joe Hart, who also missed the FA Cup tie, superbly saved an effort from Kiev scorer Vitaliy Buyalsky.
Chilean Pellegrini added: "In this profession you always get criticism when you don't win, but for the manager it is important to take the right decision.
"I always try to respect all the competitions but unfortunately we couldn't continue in the FA Cup."
City still have work to do
City are favourites to progress to the quarter-finals for the first time but Pellegrini, who will be replaced as manager by Pep Guardiola at the end of the season, warned that the tie was far from over.
"I'm very happy. It's a very good result," he said.
"I think the worst thing we can do is to think that because we won 3-1 away the game at home is finished.
"We played very well, created a lot of chances and we pressed very well."
'Good start to a big week'
City centre-back Vincent Kompany hopes the result will give his side confidence as they prepare to face Liverpool in the League Cup final at Wembley on Sunday.
"It was a great result, especially away from home, and we couldn't have hoped for better," he said.
"We will take a lot of positives out of the game and it's a good start to a big week for us."