"A setback" was how Arne Slot described his first defeat as Liverpool manager, while pundit Chris Sutton declared "the honeymoon is over".
Slot had led Liverpool to three wins out of three without conceding since replacing Jurgen Klopp in the summer.
But they were frustrated by Nottingham Forest, who claimed their first win at Anfield since February 1969 thanks to Callum Hudson-Odoi's strike.
It was not a proper smash-and-grab, but Liverpool did have the better chances - and Slot said his team made too many errors.
Liverpool were frustrated by Forest breaking up play in the first half and their best chance came when Luis Diaz struck a post.