Carlo Ancelotti was delighted with the form of his attackers after Real Madrid thrashed Salzburg 5-1 in the Champions League on Wednesday but acknowledged fixing his team's problems in defence was an ongoing concern.

Rodrygo and Vinicius Junior each scored twice in a dominant win, with Kylian Mbappe also on target as the reigning European champions made sure of a place in the knock-out stage.

Madrid conceded a late consolation, though, and are still waiting on a first clean sheet in the Champions League this season, putting a slight dampener on their celebrations.

"We have fulfilled our objective. Winning and trying to play a good game. A bit soft in the beginning, but then we fixed that and played really well," Ancelotti told Movistar Plus.

"Obviously, there is no doubt about the quality of our players up front. We are trying to fix the rest. Because the efficiency we have up top is unbelievable. We have to fix the other issues we have at the back.

"Sometimes we do well and sometimes we do less well, but we're on a good run. I'm not angry about conceding a goal, we did well at the back today.

"[Antonio] Rudiger was very good today, [David] Alaba is finally back, [Raul] Asencio is good... It's a collective problem we have. That's the key this year. If we can have collective commitment, we will be successful, and we will be able to take full advantage of the quality we have up front."

Ancelotti lamented the slow start Madrid made to their Champions League title defence after they lost three of their first five matches, which left them facing a difficult task to secure a top-eight finish and earn direct qualification for the round of 16.

Madrid are 16th in the standings on 12 points and must win their final game at Brest and rely on other results going their way to finish in the top eight.

"You never know what could happen... Only one thing is clear: we have to win the last game and that's nothing new at this club. We have to win all the games if you are at Real Madrid," Ancelotti said.