Israel's Dudi Sela played giant-killer again on Friday, upsetting sixth seed Tommy Robredo of Spain 6-4, 6-1 to sweep to his first ATP Tour semi-final at the $524,000 China Open.

The 23-year-old Sela, who knocked out top seed David Ferrer of Spain on Thursday, overcame a nervous start to steamroll the world number 16 in an impressive display of controlled aggression and clean hitting.

"I felt very confident. I knew that I had nothing to lose today ... I knew that at this moment I am playing very good and that I can win, and it paid off," a beaming Sela told reporters.

After dropping his serve early to trail 3-1 in the first set, the 92nd-ranked Israeli began attacking Robredo's serve with gusto, firing passing shots and hitting deep into the Spaniard's back-hand to force errors.

The tactic proved effective, a rattled Robredo surrendering the second set and winning only 54 percent of his first serves.

"I knew that I had to attack him, because if not, he was going to move me around," said Sela, who admitted to riding on a wave of confidence since helping Israel beat Peru to break into the Davis Cup World Group on Sunday.

Sela faces a semi-final clash with seventh seed Rainer Schuettler of Germany [Images] who upset French world number 12 Richard Gasquet 6-4, 3-6, 6-4.

Third seed Fernando Gonzalez of Spain also vies for a place in the last four with Germany's Bjorn Phau on Friday, while American Andy Roddick [Images] plays former world number one Juan Carlos Ferrero of Spain in the other quarter-final.

Former US Open [Images] champion Roddick is bidding for one of four remaining places in November's Tennis Masters Cup in Shanghai, which brings together the year's eight top-performing players.

Swiss Roger Federer [Images], Rafael Nadal [Images] of Spain, Novak Djokovic [Images] of Serbia and Briton Andy Murray have already qualified.

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