WILLIAM SISTERS WIN GOLD AT OLYMPICS.

Serena Williams followed her own Golden Slam by teaming with big sister Venus on Sunday to continue their dominance of Olympic women’s doubles tennis.

The American sisters beat Andrea Hlavackova and Lucie Hradecka of the Czech Republic 6-4, 6-4 under the roof on a rainy afternoon at the All England Club for their third Olympic doubles gold. Venus — with her red, white and blue braids pulled back into a bun — closed out the match with a backhand volley winner after the Czechs saved a pair of match points.

“We all talk about this, ‘We have so many medals,’ but to be able to add to that, it’s like an unbelievable feeling,” Venus said. “You know that in that count, there you are. It feels amazing.”

On Saturday, Serena beat Maria Sharapova 6-0, 6-1 for the singles gold. She joined Steffi Graf as the only women to complete the Golden Slam — winning the Olympics and the four majors.

When the Americans in the crowd at Centre Court broke into a chant of “U-S-A! U-S-A!” as the players left the court, the sisters each pumped their fists, turned around to wave, then slapped a high-five. The medal ceremony had to wait for the outdoor bronze-medal match, which was delayed by rain.

Serena became tennis’ first double gold medalist at an Olympics since Venus won singles and doubles at the 2000 Sydney Games. The sisters also won the doubles gold at the 2008 Beijing Olympics.