New York:Defending champion Serena Williams joined her sister Venus in the third round of the US Open with a dominating victory 6-1, 6-1 Melinda Czink of Hungary on Wednesday.
Williams offered a new, tongue-in-cheek explanation for why she plays so much better at Grand Slam tournaments than other events.
"Maybe it pays more," she said with a smile. "I guess I'm trying to pay off my mortgage."
Williams put together a near perfect match to beat 51st-ranked Czink in less than an hour as she seeks her fourth US Open championship and 12th Grand Slam singles title overall. She's won three of the past four major tournaments _ but she hasn't won a single non-major tournament in that span.
The American is trying to become the first woman to win consecutive titles at Flushing Meadows since her older sister Venus in 2000-01.
The siblings could play each other in the semifinals. Venus Williams wore heavy bandages above and below her left knee while winning earlier Wednesday, eliminating Bethanie Mattek-Sands of the United States 6-4, 6-2.
The Williamses are scheduled to team up Thursday in the first round of doubles, taking on Julie Goerges and Arantxa Parra Santonja. Serena said she hadn't had a chance to speak to Venus about whether they would stay in the doubles event but figured they would play.
The younger Williams played Czink at a hard-court tournament in California in July, and things were much more competitive until Williams eventually prevailed 6-3, 7-6 (7).
"I definitely made adjustments," Williams said. "I knew her game better today."
Czink had trouble handling Williams' power, as was illustrated on consecutive points early in the second set: First, one ball flew wildly off Czink's racket and soared wide and high, so off-track and so hard that it smacked the scorekeeping gizmo off the chair umpire's stand. Next, another ball went directly sideways, nearly into the head of a line judge.
Williams finished with an impressive ratio of 25 winners to only nine unforced errors.
About the only glitch for Williams came midway through the first set, when she thought she had pounded an ace. Instead, the serve was waved off by a line judge, who called a foot-fault.
Williams turned and glared, setting her hands on her hips. She just stood there with a straight face for a few seconds, staring down the official. When play resumed, Williams pushed a forehand into the net, then again sent a serious look in his direction.
And on the following point, Williams smacked an ace at 115 mph (185 kph) and looked over once more, as though to say, "Was my foot in the right place that time?!"
"I was kind of frustrated because I hit a great serve, best serve I hit in months. Yeah, I was just like, 'Ugh!'" Williams said.