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ATLANTA (Reuters) - Philadelphia's Roy Halladay maintained his perfect start to the season by pitching a complete-game shutout that led the Phillies to a 2-0 victory over the Atlanta Braves Wednesday.

The former American League Cy Young winner, acquired in a blockbuster trade in the offseason, struck out seven batters to improve to 4-0 in his first season for the Phillies.

"In my years here, there have been two guys that have commanded the strike zone like that, that I've actually faced," Braves veteran Chipper Jones told reporters of Halladay.

"Rocket (Roger Clemens) was the other one. What's not to be impressed about him? He's the real deal."

Halladay has allowed just three earned runs in four starts with the Phillies, who traded away their former No. 1 pitcher Cliff Lee in exchange for the long-time Toronto Blue Jays' ace.

Atlanta entered the game having won five of six including Tuesday's 4-3 comeback triumph against the Phillies. Against Halladay, however, the Braves could not muster a rally.

Atlanta's best chance to score came in the seventh where they loaded the bases with one out before Yunel Escobar grounded into a double play to end the inning.

"You get plays like that, that basically save the game for you," Halladay said. "They could have easily scored two runs."

Braves starting pitcher Tim Hudson struck out five while allowing the two runs in six innings of work.

The veteran right-hander is off to a solid start this season after making just seven starts in 2009 following his return from major arm surgery.

(Reporting by Jahmal Corner in Los Angeles; Editing by Peter Rutherford and Ian Ransom)