The dreary early evening sky and bleak digits shining off the scoreboard offered little hope, but for one moment, Varvara Lepchenko had Petra Kvitova right where she wanted her: So far off the court that the Wimbledon winner probably could have reached out and high-fived a few fans in the front row. Rather than conducting a spontaneous meet and greet, Kvitova slid into backhand she smoked up the line, making the ball look like a blur. It was the exclamation point to a declarative day of tennis.

That match point moment typified this fourth-round encounter—even when Lepchenko issued a challenge, the fourth-seeded Czech almost always responded with an authoritative answer. On a day in which defending champion Li Na was bounced out of the event, Kvitova solidified her status as a contender in rolling to a 6-2, 6-1 rout.

Clad in a plum-colored top and matching skirt over dark leggings, Kvitova's on-court attire offered an apt color scheme for a beat down. She whipped forehands, leaving bruise marks on the ball and backing Lepchenko up behind the baseline, then pulled the string on floating drop shots that befuddled her opponent. The Wimbledon champion hit 18 winners, won 21 of 24 points played on her first serve, and did not face a break point in advancing to the quarterfinals for the first time in four French Open appearances.

The match was originally scheduled for Court Philippe Chatrier, but was moved to Court 1 at 7 p.m. local time, with the center court program running long. Playing with expediency (dark clouds were aloft), Kvitova raced out to a 4-1 lead. Things happen in a hurry on court when Kvitova is cracking her returns with depth. Her predatory return posture rushed Lepchenko into successive double faults to end the 32-minute first set.

World No. 63 Lepchenko, the last American left in either singles draw, managed her nerve and game admirably in beating three-time semifinalist Jelena Jankovic in the second round, and by fighting back from a third-set hole to outduel 2010 champ Francesca Schiavone, 3-6, 6-3, 8-6. But she lacked the emotional energy that sparked her in those wins. She may have been weary from her three-hour battle with the feisty Schiavone, or hampered by her taped right ankle, or simply overhwelmed by Kvitova's onslaught. In any event, Lepchenko looked listless in falling into a 1-4 second-set deficit.

Since her run to the Australian Open final four, Kvitova has struggled with illness, injury, and inconsistency, but she has such a smooth swing that still produces easy and explosive power. When she's on, she can create angles that introduces opponents to places they usually don't visit on court.

Kvitova doesn't display the ruthless competive spirit of Sharapova, but she can do more with the ball to make opponents feel helpless. Should the only Top 5 seeds still standing advance to a blockbuster semifinal that would be a rematch of a 2012 Australian Open semi and 2011 Wimbledon final, it will be interesting to see how Kvitova's versatile and powerful all-court attack stacks up to Sharapova's formidable ground game and intensity.

—Richard Pagliaro