By Joshua Schneyer

RIO DE JANEIRO (Reuters) - The world champion U.S. women's water polo team won a spot in the Olympic semi-finals by overwhelming home team Brazil on Monday, prevailing 13-3 and moving a step closer to defending their London Games title.

In the semi-finals on Wednesday, the U.S. women will face Hungary, who edged out Australia by winning a penalty shoot-out following an 8-8 draw.

Russia's women advanced with a 12-10 win over Spain and will next face Italy, who reached the last four with a 12-7 victory over China.

The United States and Italy are the only women's teams yet to lose in the tournament but it was the U.S. lineup that produced the most dominant display on Monday as they lived up to their status as gold medal favorites.

After three U.S. wins in the group round, where the team beat Spain, China and Hungary, they faced their easiest game yet against Brazil.

Californian Makenzie Fischer, 19, helped to lead the charge with two goals, and was one of eight U.S. players to score in the first half without reply.

"Everyone is ready to step up and take a shot," Fischer said of the team.

The U.S. may face a tougher opponent in their next game.

Hungary came back from a 5-3 first half deficit against Australia, to even the score in the last quarter and go on to win a tense shoot-out.

Hungarian center-back Orsolya Takacs, 31, said her team have ample experience playing against the United States and will be studying videotape to devise a winning strategy for the match-up.

"Everybody's beatable," Takacs told reporters. "We will do everything to win."

Team USA won gold at the 2012 London Games and have clinched a spot on the podium at every Games since women's water polo was added to the Olympics in 2000. The women's gold medal match is set for Friday.

The men's water polo tournament resumes on Tuesday, when world champions Serbia face Spain in the quarter-finals, after a series of mostly disappointing performances in the group phase.

Brazil's men's team, who won three out of five group stage matches and upset the Serbian team earlier, face a strong Croatian side.

The U.S. men's team failed to qualify for the quarter-finals.

Olympic water polo teams have faced some unexpected challenges in Rio. Controversy erupted over the outdoor water polo pool conditions last week after some players complained about over-chlorination that stung their eyes.

But play has now moved to the indoor pool stadium that hosted Olympic swimming events, where there have been no complaints.

(Reporting by Joshua Schneyer; Editing by Andrew Hay, Alison Williams and Mark Lamport-Stokes)