NEW YORK (Reuters) - Persistent rain forced U.S. Open officials to abandon play early at the U.S. Open on Tuesday.

Only two of the six scheduled singles matches were completed on the ninth day of competition as heavy showers interrupted play on four separate occasions.

Tournament organizers eventually called off play in the evening session with three men's fourth round matches still in progress, all in the first set.

They had earlier called off the women's quarter-final between Maria Sharapova and Marion Bartoli after just four games, creating a backlog of matches for Wednesday.

In the only two matches that went the distance, world number one Victoria Azarenka defeated women's champion Sam Stosur 6-1 4-6 7-6 and Spain's David Ferrer beat Richard Gasquet 7-5 7-6 6-4.

(Editing by Greg Stutchbury)