Manuel Pellegrini was left frustrated after a set-piece goal set West Ham United on course for a 2-0 defeat at Wolverhampton Wanderers on Wednesday night.
Tightening up from dead balls has been a priority for the boss, so he was disappointed to see Leander Dendoncker reach Joao Moutinho's corner first to prod the home side in front and ultimately condemn the Irons to a sixth defeat in eight top-flight matches.
Patrick Cutrone notched the match-clinching second near the end, but it was the opener which Pellegrini felt gave Wolves the licence to play the game at their tempo.
He said: "Of course we wanted to win two games in a row away from home. It's not easy. We didn't play a bad game but unfortunately for us they scored from a set piece.
"We had some opportunities to draw the game, but didn't score and then after that playing 65 or 70 minutes one goal behind, they found the space for one last counter attack that decided the score.
"Conceding the first was important [towards the final outcome] because we know that they are a side who like to manage possession, so being one goal in front makes it easier for them to play."
I thought we worked well, but we didn't create the chances necessary to draw the game
After keeping a clean sheet and having defended superbly at Chelsea on Saturday, when they won 1-0, the Hammers again allowed their opponents to score without having to carve them open from open play.
"It's frustrating because the most part of our goals conceded this season have been by set-pieces," the manager continued. "You look at Newcastle, the two goals against Crystal Palace, one against Bournemouth - they are decisive goals when you want to win those games.
"In the first half it was a tight game, both teams had the same few opportunities to score, and that goal gave Wolverhampton the chance to play the game at the pace they wanted."
Pellegrini could not fault the effort of his side as they searched for a route back into the contest, but said his team need to show more composure at both ends when they face Arsenal on Monday night.
He added: "I thought we worked well, but we didn't create the chances necessary to draw the game. There was the one clear opportunity in the second half and football is like that.
"Sometimes you miss chances and sometimes you score, so now we have to look to win our home game against Arsenal."