Williams fell behind her opponent from the start of the match. A turning point was when she missed an overhead shot into the net with a score of 2-1.
Williams, who won gold metals in singles and doubles in the 2012 London Olympic Games, will leave Rio with no medals. She and her older sister Venus, who sat in the stands Tuesday, were knocked out in the first round of doubles — their first defeat in the Olympics – squashing their hopes of winning a fourth successive title.
The 20th-ranked Svitolina, meanwhile, was making her first ever appearance at the Olympic games. Williams won gold in both events in London four years ago and won her 22nd grand slam single title at Wimbledon last month.
Williams also follows the number one men’s player, Novak Djokovic, out of the competition. The current French Open and Australian Open champion was in tears after he was beaten by Juan Martin del Potro 7-6, 7-4 on Sunday and suffered more disappointment when he and partner Nenad Zimonjic lost in the second round against Brazilian duo Marcelo Melo and Bruno Soares.