If there were a war between Vietnam and China now, who would win?

Recently China seems to create another so-called 'Tomkin Gulf' by using fake fishing boats to harass and attack Vietnam's boat, then they will have reason to invade Vietnam, or at least occupy the Vietnam's sea with oil potential. The Vietnamese really do not hope a war because they experienced too many wars but it does not mean they are sacred, so they are choosing the diplomatic option now. However, if the war happens, do u believe a small country like Vietnam could defeat the second most powerful country in the contemporary world(1st is U.S of course)? Even though they did it many times in the past :">