DelPoRR

The nickname "DELPO" was printed in block letters on the back of Juan Martin del Potro's white Nike shoes, and it didn't take long for him to brand command on the match today. Navigating some slippery footing, del Potro rarely made a mis-step in stomping Marin Cilic, 6-2, 6-4, to register his ninth consecutive clay-court win without surrendering a set.

It was del Potro's third career clay-court thrashing of Cilic, who was dismissed by the Argentine in last month's Davis Cup quarterfinals, 6-1, 6-3, 6-1. But Cilic was deeply depleted in that match, having just won a five-set marathon over David Nalbandian, followed by an epic five-set doubles loss, in the prior two days. Cilic was fresher this time, but soon suffered from familiar frustration.

Both men stand 6-foot-6, but Cilic played points like he was 5-foot-6 at the outset. Looking like he wanted no part of forehand exchanges, Cilic tried to take the pace off, using the drop shot to drag del Potro forward, and shortened rallies by driving the ball down the line.

In theory, Cilic's tactics made some sense: When you've been pounded by a powerhouse and managed to win just seven games in five prior sets on dirt, you'd be compelled to change things up, too. In practice, it was a horror show. Del Potro broke at love for a 2-1 lead, soon seizing a 5-1 stronghold. Cilic, who might have been wiser to try to establish the deep ball first—in an effort to back the big man up before luring him forward with the dropper—stopped the bleeding in saving two set points and holding with an ace down the middle. But del Potro held at love to collect the first set in 35 minutes, serving 76 percent compared to Cilic's 39 percent.

In the fourth game of the second set, Cilic earned six break points, only to see del Potro rip successive aces down the T to save the last two and smash a service winner down the middle to hold for 2-all. That game typified the match: Even when Cilic made a move, del Potro always had an answer.

In the next game, del Potro looped a backhand return, then stood still as if about to contest Cilic's serve, but he opted to play on and eventually won the point. Cilic complained to chair umpire Fergus Murphy that the 10th seed had given up on the point, but to no avail. Del Potro broke for 3-2 on another error, and by the time a raging Cilic smashed his Head racquet to the clay twice, nearly decapitating its head, the end was in sight. The 2009 U.S. Open champ won 12 of the final 14 points played on his serve to close in one hour and 36 minutes.

Though he's 2,230 points behind fifth-ranked Jo-Wilfried Tsonga in the rankings, if del Potro can serve with the authority he showed at times today, a return to the Top 5 appears inevitable. He is 2-0 against quarterfinal opponent Alexandr Dolgopolov.