MIAMI, Fla.—The ball buzzed past Serena Williams so quickly at net that she barely had time to blink before taking appropriate action: She applauded. Trailing 1-4 at the outset of today's Sony Open semifinal, Williams showed respect for Maria Sharapova's passing shot by giving her rival a hand.

The world No. 1 spent the rest of the match throwing down the hammer.

Finding the range on her imposing serve, Williams reeled off five straight games to spark a 6-4, 6-3 victory and roll into the Miami final for the ninth time. It was Williams' 15th consecutive victory over the woman she's treated as her personal punching bag for almost a decade, and her 14th straight win against a Top 10 opponent.

It's been such a lopsided match-up that Sharapova herself has been reluctant to use the word "rivalry" to describe her meetings with Williams, which carry the same sense of inevitability as Sisyphus' efforts to push the rock up the hill—no matter what Sharapova does, Williams rolls right over her at crunch time.

Yet this rematch of the 2013 Sony Open final had a hopeful start for the fourth-seeded Russian, who saved two break points in each of her first two service games. Reading a wide Williams serve, Sharapova took the ball on the rise and slammed a forehand return winner down the line, eliciting a raised eyebrow from the world No. 1—and three break points. When Williams' running forehand strayed, Sharapova had the first break and a 3-1 lead after 22 minutes. She consolidated at 15 for 4-1.

Driving the ball deeper and forcing Sharapova, who had controlled the center of the court in the early stages, to counter more off her back foot, Williams broke back at 15 for 3-4.

Wearing the green and orange colors of the Miami Dolphins, the world No. 1 dialed up the blitz in the next game as she erased a break point on a gutsy 101 M.P.H. second serve, then blasted a 121 M.P.H. serve winner and held for 4-all with a 108 M.P.H. ace down the middle. A skittish Sharapova flat-lined a double fault to open the next game; five points later, Williams crunched an open-stance backhand into the corner to break for 5-4.

While Sharapova sat with an ice towel draped around her neck in a meditative state on the ensuing changeover, Williams was just getting warmed up. Cranking up her serve, she cracked three missiles in a row—the first at 117 M.P.H. and the last at 122 M.P.H.—to serve out the 48-minute first set at love, winning 10 of the last 12 points.

The 26-year-old Sharapova is at her best smacking her flat drives into the corners and playing unrelenting offense. She exploited a sloppy service game from Williams to break for a 2-0 second-set lead, but was soon haunted by familiar issues.

Williams is not only the more authoritative server—she had eight aces to none for her opponent, and backed up her second serve better—she also has a faster first step, she's more explosive in running rallies, and typically plays with more spin so she can create sharper angles. Sharapova is skilled driving the ball down the line, but those drives that help her bully lesser opponents set her up for misery against Williams, who exploits the angles Maria creates, and doesn't look too stressed doing it.

The six-time champion broke back on a double fault. Lifting her level, Williams strung together 11 straight points to break again for 4-3, eventually extending to 5-3. When Sharapova netted a backhand, Williams was through to the final, where she will meet second-seeded Li Na or 10th-seeded Dominika Cibulkova.