Ζῆν οὐκ ἄξιος, ὅτῳ μηδὲ εἷς ἐστι χρηστὸς φίλος → Life is not worth living if you do not have at least one friend.
winning the day: P. and V. κρείσσων, V. ὑπέρτερος, νικηφόρος (also Plato but rare P.).
rejoicing: P. and V. γεγηθώς (rare P.).
be triumphant: use triumph, v.