The Gunners’ summer signing scored for just the second time since his £65million-move from Chelsea to put his side 1-0 up in the 89th minute at Brentford. Havertz came on in the 79th minute to replace Gabriel Martinelli. Just 10 minutes later, he was running towards the away end doing his trade mark celebration. Bukayo Saka sent a brilliant, curling cross towards the far post, leaving …