Keys reaches tennis semis

American Madison Keys closed in on an Olympic tennis medal by reaching the women’s singles semifinals by overwhelming Daria Katsatkina of Russia 6-3, 6-1.

Earn one more victory — either in the semifinals against No. 2 Angelique Kerber of Germany, or in the bronze match — and Keys will head back home with a medal.

With a first-round loss by the top-seeded mixed doubles team of Caroline Garcia and Nicolas Mahut of France, none of the five No. 1 seeds in singles and doubles will win a medal. Serena Williams, who lost in the third round, was the only No. 1 seed to win a match.