Zambrano didn't allow a run over 6 2/3 innings and shrunk his ERA against Houston to 2.29 while improving his record to 10-5, a mark that spans 21 career games.
It was Zambrano's dominance that made the shoddy day in the field, along with the Astros' fourth shutout of the season, somewhat easier to accept.
"You have to look at the competition," Berkman said. "It's not like we came out against somebody's No. 5 starter and were shut out. You're facing probably the guy with the best stuff in the National League on a day that the wind's blowing straight in here at Wrigley Field, where you're not going to get any base hits on the ground and there's going to be no base hits in the air.
"You're pretty much going to have to hit line drives and [Zambrano] doesn't walk many guys. So, we certainly are disappointed that we lost and we played some sloppy defense which is never good, but offensively, this is one game that I can't get too upset about as far as not scoring any runs."
Berkman's 0-for-3 day at the plate will be forgotten long before his contributions during the Cubs' half of the fourth. In Berkman's words: "It was a snowball fight between me and [Lamb]. We both lost."
With Mark DeRosa on second base and one out, Geovany Soto knocked a sharp grounder to third, where Lamb trapped the ball on a short bounce and fired to first. The ball skipped in front of Berkman and skidded to the wall near the bullpen, allowing Soto to reach safely while DeRosa moved to third.
Berkman presumably thought he could catch DeRosa easing his way back to the bag after rounding third and threw back to Lamb, but the ball instead sailed into the seats behind the Cubs' dugout, much to the delight of the 41,593 fans at the Friendly Confines.
"I probably wouldn't have thrown it if I didn't think I had a shot to nab him," Berkman said. "Just an errant throw. What are you going to do? You're not going to play a whole season and not throw a couple poorly. It was one of those situations where it looked like he had rounded too far. I just tried to make a good throw and threw it in the stands."
"It kind of looked like he didn't have a play," manager Phil Garner said. "It would have been better if he would have thrown it to the third baseman instead of over his head. That would have been better."
The Astros haven't been a solid defensive team this year by any stretch, but four errors in one game is considered unacceptable by Major League standards. Berkman agreed with that assessment but pointed out the high error total is the exception rather than the rule.
"Am I proud of it? No," Berkman said. "Did we play good defense? No.
"I'm not making any excuses. That's one area where this club really needs to do a better job. Your hitting is going to be there, but defense is one thing you expect to play well consistently. And you have to play good defense.
"If you give the other team extra outs, you're going to get beaten every time. We did that today. We stunk defensively and I was a big part of that."
Jason Jennings would probably agree with that, although he reacted to this loss -- his fifth this year -- with quiet tact.
"It [making errors] changes the situation in the inning, but obviously, we didn't have our stuff together as a team today," he said. "We didn't really look good at all."
The Astros mounted a threat in the seventh, Zambrano's final inning. Carlos Lee singled to right and Loretta walked, and after Lamb lined to left for the second out, Luke Scott drew a walk off the Cubs' ace to load the bases.
Manager Lou Piniella called for right-hander Carlos Marmol to face Eric Munson, who launched a towering fly ball toward center, but thanks to the strong winds blowing in, the ball died several feet in front of the warning track.
"It wasn't like we swung the bats all that poorly," Craig Biggio said. "That's the way it is sometimes when the wind's blowing in. Munson absolutely hit his well. Other guys squared up pretty good. You can't sit here and complain about it."
"We did have a little bit going," Garner said. "Munson absolutely smashed the ball and it got knocked down. That was about the extent of what we did today."