Varvara Lepchenko transformed the terre battue into a treadmill and Angelique Kerber was doing much of the road work. Chasing Lepchenko's forehand blasts for more than two hours, Kerber stood her ground at critical moments in the decider and pounded a pair of cross-court forehand winners that proved to be game-changers.

In a punishing battle of left-handers, Kerber competed with toughness and tireless legs, scoring a 6-4, 6-7 (3), 6-4 victory to reach the fourth round of a Grand Slam for the fifth successive time. Kerber was winless in four prior meetings with the Tashkent-born Lepchenko, suffering three shutout sets in that span, and you can see why the American unsettles her. The 29th seed hits a heavy topspin ball off the forehand that forces Kerber to drop back and play shoulder-high shots that are difficult to defend. When she's in the groove, Lepchenko looks like she can hammer her forehand anywhere, scorching 38 of her 40 winners off that lethal wing.

Through first five games of the opening set, Lepchenko often took charge, but failed to land the finishing forehand. In the eighth game, Lepchenko nudged an awkward half-volley wide to face her sixth break point of the set. The ensuing 23-shot rally brought out the aggression in Kerber, who stepped forward and flattened forehand after forehand into the corners. Lepchenko finally succumbed when her lunging backhand sailed long, eliciting a "come on!" from Kerber, who had the break and a 5-3 lead. Two games later, Kerber broke for the third time to collect the first set in 38 minutes.

An emboldened Kerber won eight of the first 11 points for a 2-0 second-set lead, but Lepchenko, who punished Kerber's second serve with her forehand return down the line, broke back at 30 and navigated a deuce game to even matters. The eighth-seeded German was up 5-4 and two points from victory with Lepchenko serving when she scampered up to a mid-court sitter, but slapped a flat forehand long, clutching her head and cringing at the brutal miss. Instead of match point, it was 30-all.

Lepchenko began to grunt a little louder, create angles a little sharper, and two forehand winners later it was 5-all. Drilling a pair of forehand winners down the line, Lepchenko cracked open the tiebreaker with a 4-2 advantage. Kerber, perhaps weary from so many sprints or determined to keep the ball low and force her 5'11" opponent to bend, netted three shots in the final four points as Lepchenko snatched the 56-minute second set bolstered by a 19 to 9 edge in forehand winners.

Lepchenko, who played the first two sets wearing a heavy shirt and leggings to combat the late-day chill, took a break and came back for the decider sporting a t-shirt and skirt, revealing the physique of a powerfully-built athlete. Kerber lacks the single swing finishing power of compatriots Sabine Lisicki, Julia Goerges, and Mona Barthel, but she doesn't squander points as those three big hitters can, and she's better at reading the opponent and extending the point.

In the seventh game of the third set, Lepchenko had Kerber on the defensive, and an open expanse of red clay down the line, but she went back cross-court, where the No. 8 seed was waiting. Kerber laced a short-angled forehand winner cross-court that froze her opponent and earned break point. When a rattled Lepchenko steered a forehand down the line wide, Kerber had the lone break of the decider and a 4-3 lead. Kerber cracked another forehand cross-court and closed with an ace, winning eight of the last nine points on her serve to seal the two-and-half-hour triumph.