London, Aug. 18 -- Ruben Amorim's bold call in goal backfired as Arsenal edged Manchester United 1-0, 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 on Sunday. 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,...