U.S. tied at Davis Cup

Sam Querrey put the United States on the scoreboard with a 7-6 (1), 3-6, 4-6, 6-1, 6-4 win over Viktor Troicki of Serbia to end the first day of the Davis Cup quarterfinal with the two nations tied at 1-1 Friday.

In the first match, world No. 1 Novak Djokovic took care of 23rd-ranked John Isner 7-6 (5), 6-2, 7-5 at the Taco Bell Arena in Boise, Idaho.

The 20th-ranked Querrey kept the Americans' hopes of winning a match on the opening day of action alive when he raced through the fourth set to even the score to two sets apiece.

In the final set, Querrey broke the 44th-ranked Troicki's serve on a second break point in the ninth game when the Serbian netted a forehand. Troicki saved the first set point with an ace.

Djokovic initially trailed Isner in the first set when the American broke serve in the third game of the first set. When Djokovic recouped the service break in the sixth game he gained total control of the match.

"There's a lot at stake because there's a lot of emotions and you're playing for your country," Djokovic said. "You really want to start well and want to bring the first point to Serbia."

Although the 6-foot-9 Isner posted 17 aces, his serve let him down. The 23rd-ranked Isner put only 54 percent of his first serves into play in contrast to Djokovic, who capably put 77 percent in play.

Isner presented Djokovic with four break-point opportunities in the two-hour match and the Serbian made good on all four.

Djokovic had 10 unforced errors to 37 for Isner, which also allowed the Serbian to dominate throughout all but the first few games of the match.

"I think after the first set he became a lot more comfortable," Isner said of Djokovic. "He started playing really well.

Isner was ahead by a service break in the initial stages of the first set, breaking Djokovic in the third game when the Serb hit an unforced forehand error.

Williams sisters both make Family Circle Cup semis

Top-ranked Serena Williams ended a long and successful day for the Williams family as she and sister Venus both won twice to reach the Family Circle Cup semifinals at Charleston, S.C., and set up their first sibling showdown since 2009.

Serena won her 13th straight match by defeating sixth-seeded Lucie Safarova, 6-4, 6-1. Earlier, she topped two-time NCAA doubles champ Mallory Burdette in a third-round match moved due to Thursday's 7 1-2-hour rain delay.

Venus also had double duty, rallying past Varvara Lepchenko in three sets before ousting 18-year-old Madison Keys later on Billie Jean King Court.

The Williams sisters next go for a spot in the finals today. They haven't met in a tournament since the 2009 Tour Championships in Qatar. Serena holds a 13-10 lead, although they're 1-1 on clay.

The excitement continues today when the sisters go against each for a 24th time in their stellar careers at a venue where both have enjoyed championship moments.