Koichi won the belly dancing competition hands down.
Japan's national snow ball fighting team made a comeback to clinch the victory.
It’s first come, first served. Let’s get a move on! I really want the Fugu keychain. I don’t want to miss out on this chance.
You've hopefully seen 勝つ by now, which means "to win." This is a nouny version of that. So, what's the noun version of "to win?" It's a win or a victory.
The reading comes from 勝つ. So as long as you have some understanding of that reading, you should be able to read this one as well.