By Steve Keating

RIO DE JANEIRO (Reuters) - The United States women's basketball team will be out to prove their credentials as one of the Olympics' great sporting dynasties on Saturday when they take on Spain in the gold-medal final.

A victory over Spain, who have never won a medal in women's basketball, would mark a sixth straight trip to the top of the Games podium for the all-conquering Americans, making them one of the greatest teams to ever grace the Olympic stage.

Only the U.S. men and India's male hockey players can claim such a run of domination in an Olympic team sport.

The U.S. men’s basketball teams earned seven consecutive gold medals from 1936-1968 while India won six straight men’s hockey golds from 1928-1956.

Riding a 48-game Olympic winning streak dating back to the 1992 bronze-medal contest, the American women have an overall record of 65-3, and Spain were not one of the teams to beat them.

The U.S. women, however, are taking nothing for granted as they zero in on gold number six.

"It’s going to mean a lot," said U.S. forward Angel McCoughtry. "We’re ready for the gold-medal game. We’re not going to come out playing (around), we have to be serious and really get this.

"People might say: 'Oh, they just played Spain and beat them by 40 points.' It’s going to be a different ball game on Saturday."

The United States and Spain played early in the group stage, with the U.S. romping to a 103-63 win, and few expect a different outcome on Saturday.

Heading into their semi-final the U.S. had outscored opponents in their first six games by an average of 41.7 points.

France provided the U.S. with their toughest test of the tournament but the Americans still walked off the court with a comfortable 19-point win.

Such has been the U.S. dominance that even some of the Spanish players give themselves little hope of pulling off what would be one of the biggest upsets in Olympic Games history.

"It is impossible to beat them," said Spain forward Laura Nicholls. "But this is a final you have to see, you have play and enjoy, enjoy, enjoy. I'm sorry, but you have to be realistic.

"The United States is a dream team and it is going to be very difficult but we will fight and, above all, enjoy ourselves."

(Editing by Clare Fallon)