DelPoinsidee

Bending over the ball mark his eyes scrutinized, Juan Martin del Potro resembled an investigator searching a crime scene for clues. When del Potro wasn't inspecting marks, he was landing drives on the lines. The eighth-seeded Argentine blasted shots with authority in downsizing Jo-Wilfried Tsonga, 7-6 (1), 6-2 in the Dubai quarterfinals.

Del Potro rolled into this third straight semifinal with his 11th win in his last 12 matches. The 2009 U.S. Open champion had lost seven of his last eight matches against Top 5 opponents, but played with the quiet conviction of a man who knew he had Tsonga's number.

The thickly-built Frenchman is a physical force, but del Potro deconstructed Tsonga's multiple-choice backhand (sometimes it's a top spin two-hander, sometimes he slices it, a couple of times he went for off-balance one-handers) with precision in a four-game tear to open the second set.  The mood of the man from LeMans degenerated from distressed to demoralized. You can understand why  Del Po spikes Tsonga's stress level: He is  1-5 lifetime and can't hit through or around the big man, whose wide reach shrinks the space Tsonga tries to create.

Court positioning, balance and del Potro's superior second serve (he won 65 percent of his second-serve points compared to 33 percent for Tsonga) are among the forces that make this a problematic match-up for Tsonga, who dropped a 6-4, 6-7 (9) 6-3, decision to del Potro in last Saturday's  two-hour, 49-minute Marseille semifinal.  Both men like to dictate with their forehands, but del Po's backhand is a bigger weapon so he can play the court straight up. Tsonga, who is at his best shading a few steps to the left of the center line to fire the inside-out forehand, can get cornered on the backhand side. The explosive acceleration he generates so fluidly through contact on his forehand is lacking on the backhand as his clarity on that shot.  Trying to tease errors from his opponent, Tsonga overplayed the soft slice at the outset only to see the 6'6" power merchant earn double break point in the second game. He saved the first with a forehand volley and second with an ace, one of three aces in that game as he held to level.  Tsonga delivered a four-ace 10th game to forge a 5-5 tie after 45 minutes of play.

Del Potro dominated the tie breaker as Tsonga double faulted to donate the first mini-break and Del Po delivered successive aces to stretch the lead to 5-0. A stinging serve set up a crunching forehand cross court as del Potro sealed the opener in 61 minutes.

The showman lost the plot vs. the stoic in the second set as Tsonga tried a side-spinning backhand drop volley that sat up. Del Potro swooped in to crack the forehand pass to break for a 1-0 second set lead, that he quickly extended to 4-0.

Continuing his climb back toward the Top 5, del Potro faces four-time Dubai champion Roger Federer, who swept del Potro in last month's Rotterdam final, for a spot in the final.

Richard Pagliaro