WATCH Arsenal in the the Carabao Cup LIVE on beIN SPORTS | Sign Up to beIN to take advantage of our special new season offer | AUS | NZ

Despite a cast of new faces, Mikel Arteta's visitor proved it is still lethal from set pieces with Calafiori netting in the 13th minute. Arsenal's William Saliba backed into Turkish keeper Bayindir, who feebly batted the ball with one hand into the path of Italian Calafiori for an easy close-range header.

"Massive (result), to come here with the atmosphere and the new signings," Arteta said. "We have to be humble about how we scored the goal and the game is won in both boxes which is what we did today."

United was otherwise the better team, with close-season signings Matheus Cunha, Bryan Mbeumo missing good chances, along with Patrick Dorgu. The home side had Arsenal pinned back for most of the second period and kept keeper David Raya busy, forcing him into a diving save to stop Mbeumo's powerful header.

"I'm really proud of the guys," United boss Ruben Amorim said. "They were really brave in everything they did during the game. Congratulations for the performance. We deserved a different result.

"We need to win games but that was completely different to last season."

Set-piece specialist Arsenal has scored 31 league goals from corners since the start of the 2023-2024 season, at least 11 more than any other team, and three of its last four league goals against United have been from corner kicks.

"Like always we were working a lot on set-pieces and that is what we showed today," defender Calafiori said.

It was a frustrating afternoon for United, with several players dropping to their knees at the final whistle, while the away fans sang their traditional "One-nil to the Arsenal" song.

United had 22 shots to Arsenal's nine, including seven on target, and 62 percent of possession against a visiting side which looked nothing like a team that finished runner-up the last two seasons.

Cunha and Mbeumo, part of United's makeover after a woeful 15th-place finish last term, quickly made themselves crowd favourites and gave Amorim reason for optimism.

Cunha had three shots on target, including a rocket from a tough angle that Raya dived to push away, while Dorgu rang a shot from just outside the 18-yard box off the post.

"They created a lot, they were in the right positions," United captain Bruno Fernandes said of Mbeumo and Cunha.

"We know they are dangerous and they are a threat. We are very aware of what they can give to the team.

"It was a good first impression for them but I'm pretty sure they will do much better."

United screamed for a penalty late in the game after William Saliba's tackle on Cunha but there was no VAR check.

Arsenal's main close-season signing, Sweden striker Viktor Gyokeres, meanwhile, saw little of the ball on his Premier League debut and was substituted early in the second half.