Christophe Galtier was relieved to see his Paris Saint-Germain side bounce back from an "average" first half to beat Maccabi Haifa 3-1 in Champions League Group H on Wednesday.
The Ligue 1 champions fell behind to Tjaronn Chery's strike midway through the first half, but they went in at the break level thanks to Lionel Messi's close-range finish.
The Argentinian's goal saw him move clear of long-time rival Cristiano Ronaldo as the player to have scored against the highest number of opponents in the Champions League (39).
It also meant he became the first player in history to score in 18 different Champions League seasons.
Kylian Mbappe and Neymar added to Messi's goal in the second half as PSG won their opening two matches in a Champions League campaign for the first time since 2019-20 under Thomas Tuchel, when they went on to reach the final.
While Galtier was unimpressed with his side's below-par display in the first half, he praised his players for the way they reacted to his instructions after the break.
"We had two or three big situations in the first period and they had some too; they pushed hard in what was a big atmosphere," he told RMC Sport 1.
"We were not well organised and we were quickly cut in two. It made for a very difficult first period. We had to rectify things and after the break we were much more compact.
"The opponents are always of very good quality in the Champions League. We had to react after the first period which was average, especially on a tactical level.
"We were cut open, our team block was low and Maccabi pushed high. From the moment the front three went down to get back in the block, we were better.
"It was not a question of lack of effort, but a question of poor analysis of the pressure between our midfielders and our attacking trio."
Mbappe's strike means he has now scored 30 goals in 46 Champions League games for PSG, taking him level with Edinson Cavani as the club's highest scorer in the competition.
Like his coach, the 23-year-old was not impressed with PSG's first half and says they need to improve quickly.
"We fell asleep a bit and we conceded this first goal," he told Canal+. "Then we reacted well. We started to install our game and make differences. We were able to score the second and seal the win at the end with the third.
"We have to improve. We will have to work. We work during the week but now we have to get results quickly because the important things will happen quickly, like the World Cup."