The game, which began at 7:05 p.m. CT on Tuesday, took five hours and 36 minutes, and ended about 12 hours before the first pitch was scheduled to be thrown for the series finale Wednesday.
"It was a marathon," said Cubs center fielder Juan Pierre, who got eight at-bats and played all 18 innings. "It's just frustrating more than anything. I know everybody wanted to get it done."
It was the first 18-inning game for second baseman Ronny Cedeno, who went the distance and had seven at-bats.
"I've never played 18 innings," Cedeno said. "You're tired. Your shoulders, your legs are heavy, you're sweaty, your jersey feels heavy. My body feels tired."
Cedeno was not in the lineup Wednesday, but he was willing to help. The Cubs used all 25 players on the roster, and called up left-hander Ryan O'Malley from Triple-A Iowa to make Wednesday's start. Rich Hill was scheduled to go Wednesday but was needed in relief Tuesday. Hill threw two innings and also got the win.
The 18-inning game was the longest innings-wise since the Cubs played 18 at Pittsburgh on Aug. 6, 1989. It's the first time the team used 25 players in a non-September game since April 20, 1986, against Pittsburgh. That game was suspended because of darkness and the 17-inning affair was completed on Aug. 11 that year. The Pirates won, 10-8.
There were 542 pitches thrown, and the Cubs used 10 pitchers and the Astros had eight. The 18 combined pitchers tied a National League record for most used in an extra-inning game, also done Sept. 28, 1995, by the same two teams at Wrigley Field.
While the Cubs and Astros were battling, the Arizona Diamondbacks and Colorado Rockies were embroiled in their own 18-inning affair, which the D-Backs won, 2-1. It's the first time in Major League history two games on the same day lasted as long as 18 innings, according to Elias Sports Bureau.
Carlos Zambrano, who won Monday's game and was used as a pinch-hitter Tuesday, caught a quick nap on one of the clubhouse recliners Wednesday. The message on the clubhouse board was to "Strap it on." Having an off-day Thursday helps.
"I'll catch up on [sleep] tomorrow," Pierre said.
Welcome: The Cubs got a break as far as finding a last-minute starter. The Triple-A Iowa team was playing in Round Rock, which is about a two-hour drive away. O'Malley was 7-7 with a 4.08 ERA in 26 games (19 starts) for Iowa. He's the seventh rookie pitcher the Cubs have used this season, and the fourth to make his Major League debut as a starter.
"He's done it the hard way," Cubs general manager Jim Hendry said of O'Malley, a Springfield, Ill., native, who signed with the Cubs as a non-drafted free agent on June 7, 2002. "He's always been a fringe prospect in the past, but hanging in there. He's having a very good year."
The Cubs didn't have many options. Right-hander Wade Miller was scheduled to make a Minor League rehab start for Iowa on Wednesday, which will likely be his last such start.
"We didn't want to take a chance with Wade," Hendry said. "He's come a long way. We've come this far with Wade and he's shown progress. We didn't want to force the action."
O'Malley is friends with Cedeno, Hill and infielder Ryan Theriot, who made sure the lefty had enough gear. Theriot gave him some batting gloves and a bat.
Hendry was in contact with player development director Oneri Fleita during Tuesday's game.
"Our 'pen has done a terrific job and there have been times they've been taxed," Hendry said. "Our philosophy lately is have somebody ready fresh in case we have to make a move."
Roster move: The Cubs added O'Malley and placed left-handed reliever Scott Eyre on the 15-day disabled list because of a strained right hamstring. Eyre had problems with his hamstring in late July, and felt it again in the eighth inning on Tuesday.
"It's been sore for a while," Eyre said. "As soon as I went to run, it felt like somebody kicked me with a steel-toed boot in the butt.
"I get to let it heal completely for 15 days instead of six or seven and be one pitcher short," Eyre said. "After last night's game, it's not good to be a pitcher short. I'll be in the dugout cheering every day."
The injury looked severe. Eyre took two steps off the mound and then stopped, bending over in pain.
"It looked like someone shot me," he said. "That's what it felt like. It wasn't the pitch, it was running to first."
Old school: Theriot wasn't thinking he was a target when he pinch-hit in the sixth inning Tuesday. Astros starter Roger Clemens had hit Jacque Jones with two out and one on in the first inning, and Cubs starter Juan Mateo plunked Clemens in the fifth inning.
Clemens threw inside to Theriot, batting for Mateo, on the first pitch, and hit him on the second.
"I was going up there trying to get a hit," Theriot said. "When I was on deck, it was the first time [the thought I could get hit] crossed my mind. As a hitter, you don't want to think that because you become passive. The first pitch, when it was up and in, I said, 'OK.' It's part of the game."
However, Theriot didn't think Clemens intentionally plunked him. Home plate umpire Jeff Kellogg immediately issued a warning to both benches.
"I'm sure if he really wanted to hit me, he could've hit me square in the back," Theriot said. "It may have been one of those things, and it's part of the game."
What was really tough was that was Theriot's only at-bat in the game.
"I was sitting there in the 14th and 15th saying, 'Man, I want to go back in -- can I go back in to pitch? Can I go and hit?'" Theriot said. "That was the longest one I've been in. And now I've been hit by Roger Clemens. I'm in the book."
Schedule change: Please note the Cubs' Aug. 27 game against the Cardinals at Busch Stadium will be a 7:05 p.m. CT start, and broadcast on ESPN Sunday Night Baseball.
Minor matters: Les Walrond gave up seven runs on seven hits and five walks over 5 2/3 innings in Iowa's 8-1 loss to Round Rock. Freddie Bynum had two of the team's four hits. ... Sean Gallagher struck out 10 and gave up one run on three hits over six innings in Double-A West Tenn.'s 2-1 win over Mobile. Jake Fox had three hits. ... Class A Daytona lost both games of a doubleheader against Sarasota. Ryan Harvey hit his 18th homer in the first game, an 11-4 loss. Ryan Bicondoa gave up one run on six hits over five innings in a 1-0 loss in the second game. ... Todd Blackford gave up five runs on eight hits over four innings in Class A Peoria's 5-2 loss to Wisconsin. ... Tyler Colvin had his fourth triple in Class A Boise's 7-0 loss to Everett.
On deck: Rookie Carlos Marmol (5-5, 5.50 ERA) will face Jason Marquis (12-11, 5.71 ERA) in the series opener Friday against the St. Louis Cardinals. The game will be broadcast on WGN Radio and Comcast Sports Net.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.