NEW YORK -- Didn't take long for Serena Williams to show her fourth-round opponent at the U.S. Open where things were headed.
"The first point of the whole match," 82nd-ranked Andrea Hlavackova explained, "when I served, and she returned, like, a 100 mph forehand return, I was like, 'OK, I know who I'm playing. You don't have to prove it to me. I know."'
Monday's match was less than 15 seconds old. It might as well have been over.
Dominant from the moment she ripped that return of an 88 mph second serve, forcing Hlavackova into an out-of-control backhand that sailed well long, to the moment she powered a 116 mph service winner on the last point, Williams extended her 2 1/2-month stretch of excellence with a 6-0, 6-0 victory to get to the quarter-finals at Flushing Meadows.
Those two big zeros pretty much tell the story; it's the fifth time in her career Williams won with what's commonly called a "double bagel." Some other impressive numbers: Williams won 60 of 89 points, built a 31-9 edge in winners and improved to 23-1 since losing in the first round of the French Open. That run includes singles and doubles titles at both Wimbledon and the London Olympics.
Hlavackova knows this act all too well: She and Lucie Hradecka were the doubles runners-up at both of those events. Not that those 2-on-2 encounters helped prepare for the 1-on-1 match in Arthur Ashe Stadium on Monday.
"Singles is completely different," said Hlavackova, who chose the phrase "What can you do"? more than once when analyzing what it's like to face 14-time major champion Williams.
"My coach warned me to not go on the court and play for a score," Hlavackova said, by which she meant just trying to keep it as close as possible. "I was in the match. I was trying to figure out how to win. And when it was, like, 6-love, 4-love, 30-love, I was thinking, 'Well, I'm not playing for a score, but one game wouldn't hurt."'
Canadian Milos Raonic lost his chance to become the first Canadian to reach a Grand Slam quarter-final since the Open era began in 1968, falling to Olympic champion Andy Murray of Britain 6-4, 6-4, 6-2.
Next for the fourth-seeded Williams, who won the U.S. Open in 1999, 2002 and 2008, is a match against former No. 1 Ana Ivanovic, who reached a Grand Slam quarterfinal for the first time since winning the 2008 French Open by defeating 55th-ranked Tsvetana Pironkova of Bulgaria 6-0, 6-4.
Williams -- who lost in doubles with older sister Venus on Monday night -- is 3-0 against Ivanovic, including a straight-set victory in the fourth round at Flushing Meadows last year.
Must not have left much of an impression on the American, because when asked what she remembers most about their most recent match, Williams replied: "Was it here?"
Assured that it was, in 2011, Williams said with a smile: "OK. Yeah, I remember, clearly, not a lot, but I will be looking at the film."
In the semifinals, the Williams-Ivanovic winner will meet either No. 10 Sara Errani or No. 20 Roberta Vinci, doubles partners who both eliminated higher seeds Monday and now face the uncomfortable prospect of trying to beat a best buddy.
"Our friendship won't change, no matter what, no matter who wins," said Vinci, noting that she expects they'll have dinner together, as usual, Monday and Tuesday. "It definitely won't be an easy match from a mental perspective. We know each other well. We practice together often. We play doubles together. We know everything about each other."
Errani and Vinci teamed up to win the French Open doubles championship in June, and now one of them is going to be the first woman from Italy to play in the U.S. Open semifinals since the professional era began in 1968.
Errani, the runner-up to Maria Sharapova at the French Open, got past No. 6 Angelique Kerber of Germany 7-6 (5), 6-3.
Vinci stunned No. 2 Agnieszka Radwanska 6-1, 6-4.
-- The Associated Press