TOKYO—Team USA extended a historic run of championships in Olympic women’s basketball on Sunday, winning the gold against home team Japan in their first-ever medal match. The United States’ women earned their seventh-straight gold in the 90–75 victory at the Saitama Super Arena, north of Tokyo. Brittney Griner, who plays for the WNBA’s Phoenix Mercury, led Team USA with 30 points. “Seven in a row, that’s pretty amazing,” Griner said, cradling her newly won medal, her second after claiming gold in Rio de Janeiro in 2016. “COVID and everything that we’ve had to get through, to finally get to the gold game, get the gold, it’s like the icing on the cake,” she said. “It just washes away everything.” The U.S. women’s victory on Sunday was their 55th straight win in Olympic game matches, and earned them a ninth championship since 1976. Japan took the silver, their first, while France …