Liverpool could feel the knock of opportunity. Chelsea’s shock home defeat to West Brom earlier in the day had blown the doors off their security in fourth place and how Liverpool made capital. Jürgen Klopp’s team have enjoyed themselves in London this season and the trend continued with a fifth win in six visits to go with the draw at Fulham. Rather abruptly, they are within touching distance of a Champions League finish via the Premier League. This was not just a victory; it was a controlled detonation of Arsenal, who were unable to show any attacking spark. It was all Mikel Arteta’s team could do to cross halfway and it was difficult to remember them creating a chance. Liverpool called the tune from the first whistle and the only question came to concern whether they could show the needed cutting edge. They gave their answer shortly after Klopp had made a bold substitution just after the hour – sending on the attacker Diogo Jota for the left-back Andy Robertson. Three minutes later, Jota had thumped home a header from Trent Alexander-Arnold’s cross and it was the prompt for Arsenal to lose the only thing that they had brought to the occasion – their defensive resilience. Alexander-Arnold has endured a difficult period with his exclusion from Gareth Southgate’s England squad but he was excellent here, with Klopp noting that he had benefited “100%” from not playing during the international break. The right-back had a smaller part in his team’s other goals. For the second he played a pass inside to Fabinho, whose ball over the top saw Mohamed Salah get away from a weak Gabriel challenge, and for the third he seized upon a loose clearance from Gabriel. From there, Salah crossed, Sadio Mané spun and provided a little touch and Jota rammed home. The hard truth for Arsenal, as Arteta suffered one of his worst matches in charge, was that the scoreline should have been heavier. The floodgates threatened to open after Jota’s first goal and Salah would be denied by Bernd Leno in a one-on-one. At the very end, Salah also narrowly failed to play in Mané. Arsenal, so frustrating and erratic, must show a better face in their Europa League quarter-final first leg at home to Slavia Prague on Thursday. “We need to apologise to our fans – the standard was nowhere near what we want,” Arteta said. “I am fully responsible. We were extremely poor. When you don’t do the basics, you don’t have a chance to compete. We looked tired but it was more of a mental issue. We didn’t win enough duels and we gave away so many easy balls. It’s very frustrating – a big shock to the system.” Liverpool have the small matter of a Champions League quarter-final first leg at Real Madrid on Tuesday but Klopp made precious few concessions towards that in terms of his selection. Gini Wijnaldum came on as a late substitute, having played in all three of the Netherlands’ games during the break, including the 7-0 win over Gibraltar but, him apart, Klopp went as strong as possible. Liverpool’s counter-pressing was close to perfect. They did not allow Arsenal to play from the back or get out at all and, from an early juncture, the game took on the characteristics of a siege. All the intensity came from the visitors. They dominated in the 50-50 challenges, with Fabinho particularly imperious in midfield. Arteta saw Kieran Tierney limp off with knee trouble in first-half stoppage time while he had been without the injured David Luiz (who may need knee surgery), Bukayo Saka and Emile Smith Rowe plus Granit Xhaka, who was ill. The selection issues did not help but Arteta refused to use them as an excuse. Liverpool created one big first-half chance when Alexander-Arnold won the ball high up off Dani Ceballos, swapped passes with Roberto Firmino and pulled back for James Milner, who had time and space. He dragged wastefully wide. There were other flickers when Mané headed at Leno and also nearly found Salah with a cut-back. Firmino lashed a low shot wide. The pattern did not change in the second-half – Liverpool manipulating the ball, working a few switches, trying to create room up the sides; Arsenal clinging on. Klopp was rewarded for his bravery with the Jota substitution, which saw Milner drop into left-back and the new man take up an inside-left attacking position, with Mané outside of him. Alexander-Arnold’s cross for Jota was a beauty and the contrast between Liverpool’s home and away form goes on. Their most recent six victories in the league have all been on the road – their longest such sequence since 1955. “This was a very important statement from us,” Klopp said. “We have to win our games and make pressure [on the top four] and that’s what we did here.”