By Jude Summerfield Manchester United were denied a smash-and-grab victory after Mason Mount scored his first goal for the club in second-half stoppage time as Kristoffer Ajer netted a 99th-minute equaliser in a dramatic finale on Saturday night. The Bees couldn’t open the scoring despite dominating the first half and out-shot the Red Devils by 31 shots to ten in total but no breakthrough came until two goals arrived in the space of four minutes. The result sees Man Utd lose more ground on top-four rivals Aston Villa and Tottenham, while Brentford remain without a win since February and are on…