Sentence:  An utterly emphatic 5-0 victory was ultimately capped by two wonder strikes in the last two minutes from Aston Villa midfielder Gary Gardner. Before that, England had utterly dominated to take another purposeful stride towards the 2013 European Championship in Israel. They have already established a five-point <WSD>buffer</WSD> at the top of Group Eight. 
Meaning of the word marked with <WSD> tags:  A gap that isolates or separates two things.