Serena Williams follows through on a serve during her overwhelming 6-1, 6-2 victory over Sara Errani of Italy in the U.S. Open women’s semifinals. Williams, who enjoyed a 38-6 advantage in winners, will play Victoria Azarenka for the title. (Kevin Lamarque/Reuters)

At 5 feet 4 and 132 pounds, Italian doubles specialist Sara Errani was barely a speed bump Friday on Serena Williams’s charge toward the U.S. Open final.

The quick reflexes, impressive foot speed and deft volleys that have made Errani the world’s top-ranked doubles player amounted to little against Williams’s overpowering serve and groundstrokes on the Arthur Ashe Stadium court, where the American won the first of her three U.S. Open titles at age 17. Friday’s showdown between them lasted just 64 minutes, with Williams dispatching Errani, 6-1, 6-2, to earn her sixth appearance in a prime-time Saturday women’s final at Flushing Meadows.

Perhaps top-ranked Victoria Azarenka will pose a more formidable challenge.

The 23-year-old reached her first U.S. Open final earlier in the day by winning an ear-splitting battle of power and nerve against Maria Sharapova, the tournament’s 2006 champion and crowd favorite, 3-6, 6-2, 6-4.

It has been a breakout year for Azarenka of Belarus, who won her first major (the Australian Open) and reached No. 1 in the world. But her record against Williams is 1-9.

“I definitely need to find something to surprise her tomorrow because she’s in great form, feeling really confident right now,” Azarenka conceded. “You know, she has everything on her side.”

Errani’s futility against Williams, whose 14 Grand Slam titles lead all active players, hardly made her unique. She simply joined a long list of challengers who failed to win a set against Williams in this tournament.

The most vexing problems for Errani were the lack of pace on her serve (which averaged 83 mph, compared with Williams’s 108) and shallowness of her groundstrokes, both of which allowed Williams to step well inside the baseline to counter.

Williams made the adjustment with ease in the opening game and bolted to a 5-0 lead, finishing with 38 winners to the Italian’s six while never facing a break point.

Afterward, Errani declined to second-guess her tactics against the woman she considers the best player in the world.

Errani focused on defending, standing well behind the baseline, in the first set. When that failed, she tried attacking in the second set, to no avail.

“I think Serena is another level,” Errani said.

The far more competitive semifinal was between Azarenka and Sharapova, who split the season’s first two majors, with Azarenka winning the Australian and Sharapova completing a career Grand Slam by winning the French Open.

They also claimed the bronze and silver medals, respectively, at the London Olympics, while Williams won gold.

Azarenka held a 5-4 edge over Sharapova entering the match, including straight-sets victories in their two hard-court meetings this year. While their 10th confrontation on Friday was a protracted affair with multiple momentum swings, that didn’t make it entertaining or even pleasant.

The 6-foot Azarenka and 6-2 Sharapova are two of the more powerful hitters in women’s tennis. But unless forced, they refuse to do anything but blast shots from behind the baseline, rarely attacking the net, volleying, slicing, varying the tempo or employing tactics other than bludgeoning the ball. And when it comes to decibel level, they have no peer, shrieking every time they strike the ball.

Even before Friday’s first point, CBS commentator Mary Carillo predicted “a grunt-a-palooza.” But the match was more like an operatic screech-fest, in which two sopranos were being strangled to death for 2 hours 42 minutes.

Sharapova came out blazing, breaking Azarenka’s serve twice and holding her own shaky serve to take a 5-1 lead. Azarenka was tentative, by contrast, seemingly seized by nerves.

Sharapova rolled on, breaking Azarenka to open the second set. But with a chance to win in straight sets, Sharapova coughed up a clutch of double-faults.

The serve has been Sharapova’s chief vulnerability since she had shoulder surgery in 2008. She has retooled her service motion, but remains prone to double-faulting at critical junctures. It cost her any chance at salvaging the second set, particularly with Azarenka gaining confidence.

The third set lasted 74 minutes, longer than the entire Williams-Errani match. The score knotted at 4, Azarenka got the service break she needed, and she dropped her racket in dazed disbelief when Sharapova’s final forehand sailed long.

Asked afterward what Azarenka had to do to beat Williams on Saturday, Sharapova noted that she wasn’t the Belarusan’s coach.

“There’s a reason why everyone is in the draw,” Sharapova added. “There is a reason why everyone puts the net up in the morning for us to play matches.

“No matter who is going in there as the favorite, no matter how confident they are, everyone has a chance.

“She’s No. 1 in the world, and there is no reason why she shouldn’t have a chance.”

U.S. Open notes: With rain forecast Saturday, officials moved up the first men’s semifinal, No. 3 seed Andy Murray against Tomas Berdych, to 11 a.m. It will be followed by Novak Djokovic against No. 4 seed David Ferrer of Spain. The women’s final is scheduled to start at 7 p.m.

Earlier Friday, twins Bob and Mike Bryan won their fourth U.S. Open men’s doubles title, 6-3, 6-4 over Radek Stepanek and Washington Kastles veteran Leander Paes.