Klopp’s gamble in making six changes to his Liverpool line-up backfired as West Ham misfit Gianluca Scamacca struck in each half – the first resulting from a bad error by goalkeeper Caoimhin Kelleher.
With the Anfield atmosphere less colourful than usual as part of a fans’ protest, the Europa League favourites struggled forcing Klopp to make a triple change at half-time – including the introduction of Mo Salah.
By then, Atalanta led when Scamacca’s speculative strike squirmed under the body of Kelleher. And the big Italian, who was part of West Ham’s Europa Conference-winning campaign last season, extended the visitor’s lead with a cute first-time finish after an hour.