Arizona's Stephen Drew points skyward as he crosses home plate after hitting a home run against Chicago's Carlos Zambrano in the fourth inning. The Diamondbacks won, 3-1, Wednesday in Phoenix.

Phoenix ? Brandon Webb won the duel in the desert.

Webb shut down the Chicago Cubs with his superb sinker, and the young Arizona Diamondbacks got home runs from two of their kids in a 3-1 victory Wednesday night in their NL playoff opener.

Stephen Drew homered in the fourth off Chicago ace Carlos Zambrano, pulled after six innings and only 85 pitches.

Right after he left, Mark Reynolds homered on the fourth pitch from reliever Carlos Marmol to break a 1-all tie in the seventh. Pinch-hitter Conor Jackson added a sacrifice fly, and the Diamondbacks got two scoreless innings from their strong bullpen.

Webb, the reigning NL Cy Young Award winner, allowed four hits and struck out nine over seven outstanding innings in his postseason debut. He walked three and hit a batter.

“The most exciting game so far,” Webb said. “I was able to keep them off-balance. I had pretty good stuff tonight, great off-speed. Had some great strikeouts, key situations.”

The Cubs, in search of their first World Series championship in 99 years, twice got the leadoff batter to second with no outs early in the game but came away empty.

Game 2 is tonight, with Ted Lilly on the mound for Chicago against Doug Davis.

Zambrano gave up four hits, struck out eight and walked one before he was lifted by manager Lou Piniella in a questionable move.

“He probably could have gone another inning. We’re bringing him back Sunday on three days’ rest,” Piniella said. “I took a shot with my bullpen. It didn’t work today. They’ve done it all year.”

Not this time. Planning for Game 4 might have cost the Cubs in Game 1.

The showdown between 18-game winners was as advertised, with Zambrano matching Webb pitch for pitch through six innings.

With Zambrano gone, Arizona went ahead in the seventh. Reynolds hit Marmol’s 2-1 pitch just over the left-field fence for a 2-1 lead. Chris Snyder walked and went to third on Augie Ojeda’s single before Jackson came through while batting for Webb.

Marmol had allowed only two runs in 25 innings after Aug. 10 for a 0.72 ERA.

“His numbers are video-game numbers with the strikeouts and so forth,” Diamondbacks manager Bob Melvin said. “Zambrano the same way.”

Arizona setup man Brandon Lyon threw a perfect eighth, and Jose Valverde earned the save.

Valverde walked pinch-hitter Daryle Ward with two outs in the ninth to bring up Alfonso Soriano.

Soriano, though, bounced into a game-ending forceout that capped an 0-for-5 night.