The Reds suffered final day heartbreak at the end of the 2011/12 after Manchester City snatched title victory from United's grasp with virtually the last kick of the season.
Law says United's last-gasp 3-2 win over City earlier this month was a key result, but insists titles are not won at Christmas.
"It was good result for United. Any result away from home is a good result but to win against your rivals and stretch the lead to six points...it's a big gap," Law told ManUtd.com.
"As we saw last season though teams can be six points ahead or six points behind but it's never over until you get to the stage where you know you can't lose or you know you can't win. Until that day, it's fatal to say who is going to win the league."
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