By Martyn Herman LONDON (Reuters) – Harry Kane’s double gave Tottenham Hotspur a shock 3-2 win away at leaders Manchester City after Liverpool came from a goal down to beat Norwich City 3-1 on what could prove to be a pivotal day in the Premier League title race on Saturday. City seemed to have salvaged a point when Riyad Mahrez fired home a penalty in stoppage time at the Etihad, but Kane capped a superb display to head home a dramatic winner three minutes later. Chasers Liverpool had earlier been give a fright when they trailed struggling Norwich midway through the second half at Anfield. Bu…