Arsenal won at least 1-0 in the trip to Crystal Palace in the second week in the Premier League.
Ps only two minutes into the game, the Gunners risked through Gabriel Martinelli, but his shot was blocked.
Eddie Nketiah (29′) also had a good chance to score, while his shot hit the right post.
Crystal Palace began to suffer from this pressure from the visitors and took a risk through Jordan Ayew, who fell in the area, but the referee signaled that the game should continue.
The second 45 minutes were even more dramatic as Arsenal won a penalty in the 54th minute after Sam Johnstone conceded a penalty.
Martin Odegaard took responsibility, who was accurate from the penalty spot and scored the only goal for the Gunners.
However, Arsenal were left with ten men on the pitch as Takehiro Tomiyasu picked up his second yellow card within seven minutes.
Eberechi Eze (73′) asked for a penalty, after he was brought down in the area by an Arsenal player, but the referee was silent again.
Arsenal managed to hold on until the end, to get the second three points, in two games played, while in the third round they meet Fulham.