By Daniel Orme Thomas Frank insisted Kai Havertz should have been sent off before he scored Arsenal’s dramatic winner on Saturday. The Gunners saw off Brentford 2-1 at the Emirates Stadium with Havertz heading home in the 86th minute to seal all three points. The win sees Arsenal claim top spot in the Premier League ahead of Sunday’s clash between Liverpool and Manchester City. Frank hailed his side for their performance but was fuming that Havertz even had the opportunity to score in the first place. The German was booked in the first-half for an elbow on Kristoffer Ajer before then falling u…