The 26-year-old Vetter, who produced the 2nd best mark in history of 94.44m two years ago in Luzern, in his openning round managed to throw 89.24m to beat Olympic champion Thomas Rohler.
"There is still a lot of room for improvement, and I am glad that I was able to complete six attempts today." said the 2017 World javelin champion Vetter, who has been battling injuries for the past two years.
European and Olymipic champion Thomas Rohler achieved modest 81.51m to take second place.
Jamaica's Danniel Thomas-Dodd womn the women's shot put with 19.08m, while Tobias Dahm of Germany claimed the men's shot put with 19.65m.
Martin Wierig threw 64.69m to win the men's discus. Olympic bronze medalist Daniel Jasinski with 62.49m was second.