Three Houston pitchers made appearances in that inning. Reed Johnson began the frame with a base hit off Chris Sampson, and Mark DeRosa followed with a double to right, pushing Johnson to third.
Kosuke Fukudome tied the game with a sacrifice fly to center. Sampson intentionally walked Daryle Ward to load the bases, and Wesley Wright, who was called in to face left-handed hitting Mike Fontenot, instead faced a right-hander when Cubs skipper Lou Piniella countered with Geovany Soto.
Wright struck out Soto and was replaced on the mound by Brocail, who worked Soriano to a 1-2 count before giving up the home run, Soriano's 20th of the season.
"It was a pitch that [Brocail] didn't get where he wanted," Cooper said. "He wanted to bounce a slider and ended up hanging it. When you hang it to guys like [Soriano], they'll make you pay."
Said Brocail: "It bounced, as a matter of fact, it acted like the first fastball that he fouled off. It was at 90 or 91 [mph]. If you watch it on video tape, it looks like a heater. I missed my spot. He got it. I've given up enough in my career, I knew it was out."
The Astros played catch up for most of the day after starting lefty Wandy Rodriguez put the Astros in an early hole by allowing six runs in the first two frames.
The Cubs scored four times in the second after Henry Blanco began the rally with a leadoff double. Rich Harden reached on a bunt single, and after Soriano drove in Blanco with a base hit, Derrek Lee loaded the bases with a single to right.
Rodriguez then issued a four-pitch walk to Aramis Ramirez, plating Harden. Soriano scored on Johnson's sacrifice fly, and Mark DeRosa capped the frame with an RBI single.
"Today, in the first two innings, I felt bad," Rodriguez said. "I didn't feel comfortable on the mound. In the last three innings, I felt better."
Cooper cited command issues as the culprit for Rodriguez's struggles.
"Sometimes, when you don't have good command and you don't make quality pitches, it'll hurt you sometimes," Cooper said. "Wandy didn't seem like he really, really had it today. He righted the ship in the third and fourth and fifth and pitched pretty good and gave us a chance."
Harden kept the Astros at bay until the fifth. Ty Wigginton opened the frame with a homer to left-center, and after Darin Erstad singled to left, he scored on Kazuo Matsui's triple to the corner in right.
The Astros narrowed the deficit to a single run in the sixth when Geoff Blum launched a two-run homer to right, and Carlos Lee pushed his team ahead by a run with a two-run homer off Bob Howry in the seventh. That lead quickly evaporated, however, when the Cubs rallied in the bottom of the frame.
"It was definitely an outstanding comeback today," Cooper said. "Guys continued to battle. [We got] down, and I felt like the Cubs, a first-place club and a talented club like that, it's kind of tough to come back. But we got some big hits and everybody played well."