That would be the 1958 match. The real question is what happened in 1954.

From wikipedia:

"This edition(1954) was the one with the highest goal average of all cups, with 140 goals in 26 matches, an average of 5.38 goals per match. This record was mainly provided by the results of Group 2, which had Hungary, West Germany, Turkey and South Korea, having thrashed in all matches (West Germany 4 – 1 Turkey; Hungary 9 – 0 South Korea; Hungary 8 – 3 West Germany; Turkey 7 – 0 South Korea; Germany 7 – 2 Turkey). In addition, there were results like Uruguay 7 – 0 Scotland, Austria 5 – 0 Czechoslovakia, Germany 6 – 1 Austria and Austria 7 – 5 Switzerland, the latter being the match with the highest number of goals in all Cups."

I think after that the national teams became more aware of the importance of defense and tactical planing.

Basically, people were just really fucking excited because it was in Switzerland, no really.