Serena Williams completed a sibling sweep Saturday, leaving the U.S. Fed Cup team on the verge of beating Belgium.
Playing Fed Cup for the first time since 2003, Williams beat Caroline Maes 6-1, 6-4 to give the Americans a 2-0 lead in the best-of-five opening-round match.
Older sister Venus Williams wobbled in the wind, but rallied to beat Kirsten Flipkens 7-5, 6-2. Struggling early with gusty conditions, Venus fell behind 5-3 before winning 11 consecutive points to take charge.
"Down that first set, it's comforting to know if anything goes wrong, Serena Williams is going to play the second match," Venus said.
The Americans were heavily favored due to the absence of Belgium's top players, No. 1-ranked Justine Henin and No. 4 Kim Clijsters, who declined to take part.
Singles matchups will be reversed Sunday, followed by the doubles. The winning team will face the winner of the Russia-Spain match in the semifinals following Wimbledon in July.
Russia took a 2-0 lead over Spain on Saturday in Moscow. France and Italy, both playing at home, also took 2-0 leads.
The Williams sisters agreed to play against Belgium in part because the site of the match is only a half-hour drive from their home in Palm Beach Gardens. Friends, family and designers from Venus' fashion business were in the stands, and the sisters gave them plenty to cheer.
"The conditions are tough," Serena said. "It was really windy, and balls are bouncing funny. But America is up 2-0, and we hope to improve it Sunday."
Serena took a 5-0 lead after only 17 minutes, and when Maes held for 5-1, the Belgian grinned at the achievement. Serena struggled with her serve, but slammed backhand winners into both corners and moved well, showing no signs of the groin injury that forced her to retire from a match last week at Charleston, SC.
She won points even when Maes had her on the run, backpedaling after a lob and smacking an overhead winner from near the baseline, then yanking a running backhand lob crosscourt for another winner.
Venus started more slowly and was three points from losing the first set.
Flipkens double-faulted to lose serve and make it 5-4, then double-faulted again on break point to fall behind 6-5. Venus closed the set with an overhead slam, then pulled away in the second set, winning the final five games.
Venus said she struggled early with the wind and rushed some shots.
"I was rushing because I wanted to hit great shots," Venus said. "Sometimes it's not about the great shots. Sometimes it's about the good shot. I love greatness, but sometimes it's goodness."
Flipkens, ranked No 132, looked relaxed at the outset, started with an ace and won the first game at love. Conditions were so windy that the hem of Venus' skirt occasionally blew up around her waist, and she double-faulted three times to fall behind 4-2.
But Venus began to hit her groundstrokes more confidently as the match progressed, and she won her final six service games.