Serena Williams sloppy in Rio de Janeiro upset

RIO DE JANEIRO, Aug. 9 (UPI) -- Tightlipped and head-bowed is not how Serena Williams envisioned leaving Rio de Janeiro.

But the world's No. 1 women's tennis player won't defend her Olympic gold medal, after losing in the third round of singles play Tuesday. The American was knocked out 4-6, 3-6 by Ukrainian Elina Svitolina. Svitolina is ranked No. 20 in the WTA Rankings.

The round of 16 exit adds to a pile of disappointment for Williams in the Summer Games. She was previously knocked out of doubles play while playing with sister Venus.

Williams was overmatched in the first set and attempted to fight back in the second. She made the score 3-3 but lost her next service, sending five double-faults into the net.