LONDON, Aug. 17 (Xinhua) -- Ruben Amorim's bold call in goal backfired as Arsenal edged Manchester United 1-0 on Sunday, thanks to Riccardo Calafiori's first-half header.

Manchester United invested over 200 million pounds (271 million U.S. dollars) in a summer overhaul but chose not to sign a new goalkeeper. With Andre Onana sidelined by a hamstring injury, Amorim chose Turkish international Altay Bayindir over veteran Tom Heaton.

That decision proved costly after just 13 minutes. Declan Rice's curling corner swung under the crossbar, with Bayindir pinned to his line and only able to push the ball into Calafiori's path. The Italian defender converted from close range for what proved to be the decisive goal.

The scoreline was harsh on the host, who showed clear signs of progress compared to last season. Amorim's side enjoyed the majority of possession, created better chances and registered far more attempts on target.

But Arsenal's David Raya produced a commanding display between the posts, denying Matheus Cunha on three occasions and diving sharply to his left to block a Bryan Mbeumo strike after the break.

Rice almost added a late second with a free-kick, and Mikel Arteta's side held firm to secure its fifth win in six league meetings with Manchester United.

"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," said Arteta.

"I look at the players' faces and they want much more. We know that we are much better than certain moments we played," he added.

His Manchester counterpart Amorim emphasized that his side played better, but still left much to be desired.

"We need to defend set pieces. There are a lot of things that we need to work on," he said. Enditem