The United States, paced by Chris Humbert's three goals, virtually assured itself of a spot in the quarterfinals of the water polo tournament by beating Ukraine 9-7 Monday.
The Americans (2-1) still have to play Croatia and Romania in the preliminary round-robin group. While Croatia is one of the stronger teams, Romania has been the weakest.
Four teams from each of the six-nation groups advance to the quarterfinals, when the tournament becomes single elimination.
Humbert, who scored four goals in Sunday's late-night 9-7 win over Greece, now has eight in three games.
Against Ukraine, the Americans couldn't convert early in the game. The game was tied 7-7 in the fourth period when U.S. luck seemed to turn.
Vadym Rozhdestvensky hit the bar for Ukraine, then Chris Oeding's second goal at the other end of the pool put the Americans ahead to stay, sending the crowd of 4,000 at Georgia Tech Aquatic Center into a frenzy.
Humbert then hit another of his trademark backhand shots with 1:53 left to give the Americans their first two-goal lead. Chris Duplanty made a good save when the United States was down a man and Mike Evans made a key block to preserve the American victory.
Earlier, defending champion Italy posted its third straight victory, beating Croatia 10-8 to move into the quarterfinals.
Hungary, which is in a different group, also went to 3-0 and earned a place in the quarters by beating the Netherlands 10-8 behind four goals apiece from Tibor Benedek and Zsolt Varga.
Yugoslavia beat 1992 silver medalist Spain 9-7, and Russia defeated Germany 10-8.
Greece, beaten by the United States on Sunday, posted its first victory, beating Romania 8-5.