Liverpool goalkeeper Alisson Becker made a brace of costly errors as the 10-man Reds lost 3-1 at Arsenal to see their lead at the top of the Premier League cut to two points.The Gunners themselves had gifted an equaliser to the visitors as a Gabriel Magalhaes own goal on the stroke of half-time cancelled out Bukayo Saka's opener.But Mikel Arteta’s men would ultimately run out winners as a mix-up between Virgil van Dijk and Alisson allowed Gabriel Martinelli to round off a fine individual performance by re-establishing the lead before substitute Leandro Trossard fired straight through the goalkeeper’s legs in stoppage time.It is just a second league defeat of the season for the Reds, who struggled to get into the game for the majority of the first half at the Emirates Stadium and ended with a numerical disadvantage as Ibrahima Konate was sent off late on.Martinelli once again shone against Liverpool, hitting his fifth goal against Jurgen Klopp’s side – the departing German no doubt looking forward to seeing the back of a player he once described as "a talent of the century".Arsenal were without Gabriel Jesus, injured once more, but took the lead against Liverpool for the fourth Premier League encounter in a row.They started well here, too, David Raya claiming a routine cross before bowling the ball out to Martinelli, whose pace was enough to see off Konate but Saka could not make telling contact as he met the cross with a diving header.Arsenal have made a habit of scoring early against Liverpool, however, and that trend continued as Saka made amends in the 14th minute.A great pass from Martin Odegaard found Kai Havertz in space, the German forward breaking through on goal only to shoot straight at Alisson, with Saka on