Illness forced No. 1-ranked women's tennis player Serena Williams to forfeit her second-round doubles match at Wimbledon on Tuesday. Williams and her sister Venus withdrew from a match against Kristina Barrois and Stefanie Voegele after three games.

Serena, who Wimbledon and WTA officials said suffered a viral illness, appeared disoriented during pre-match warm-ups. She had difficulty catching balls gently tossed to her from ball kids, and whiffed on several practice swings.

The start of the match was delayed for more than 10 minutes as doctors examined Serena. During the exam, Serena bent over and covered her face with her hands. Her physical condition showed no sign of improvement when the match began.

While serving in the third game, Serena was broken at love with four double faults. She struggled with her serve, bouncing several balls that failed to reach the net.

The chair umpire Kader Nouni eventually climbed down at love-40 and walked toward Serena to speak with her. When play resumed, Serena double-faulted. The sisters then walked toward the sideline holding hands.

And Nouni announced to the crowd at No. 1 Court: "Ladies and gentlemen, unfortunately Miss Williams has to retire."

At that moment, the 32-year-old Serena began walking off the court, wiping tears from her eyes as a stunned crowd looked on. Serena and Venus have won five doubles titles at Wimbledon.

"I am heartbroken I'm not able to continue in the tournament," Williams later said in a statement. "I thought I could rally this morning because I really wanted to compete, but this bug just got the best of me."

Alize Cornet eliminated Serena from singles competition in the third round on Saturday. Serena has won 17 Grand Slams singles titles, five at Wimbledon.