"I just have to go to bed," he said.
The Cubs will announce Wednesday's starter later. If you didn't stay awake for Tuesday's marathon, here's what happened in the 18th:
Aramis Ramirez doubled to lead off against Dave Borkowski (1-1) and reached third on Jacque Jones' single. Two outs later, Michael Barrett was intentionally walked to load the bases for Murton, who slapped a single to right.
Did Murton's approach change because Barrett was walked?
"Nothing changes," Murton said. "You have an opportunity to drive in runs. You try to muster everything you have left mentally to stay focused in the at-bat. I was able to find a hole."
Murton didn't play all 18 innings; Juan Pierre, Cesar Izturis, Ramirez, Jones, John Mabry and Ronny Cedeno did. But just playing 10 innings is exhausting.
"That's part of the game," Murton said.
Could he pitch tomorrow? The Cubs are shorthanded.
"If need be, maybe left-handed, screwball or something," Murton said, laughing. "We'll have to see."
Everybody got to play. Carlos Zambrano, the winning pitcher Monday night, was called upon to pinch-hit in the 14th, and he grounded into an inning-ending double play. Carlos Marmol pinch-hit in the 17th.
The last time the Cubs used all 25 players in a non-September or October game was April 20, 1986, against the Pirates. That game was suspended because of darkness and completed on Aug. 11 that year, lasting 17 innings.
Tuesday's game was the longest game the Cubs have played this season, both in terms of innings and time, topping a 14-inning game on June 2 against St. Louis.
"I've only actually had one other [extra-inning game] since I started -- it was in the Minor Leagues, and we played 18 innings," Murton said. "What happens, especially after the fifth, sixth at-bat, is you feel like you're in the twilight zone. You have to fight it."
The Astros appeared to have the edge when the game started. Roger Clemens had 345 career wins. His opponent, Juan Mateo, had pitched 340 innings in the Minor Leagues.
Mateo did his job, giving up two runs on four hits and one walk over five innings. He was in line for the win, departing with a 5-2 lead. But the Astros rallied with a four-run sixth inning and took a 6-5 lead on a two-run triple by Adam Everett and a two-run double by pinch-hitter Orlando Palmeiro.
"The kid gave us what we wanted," Cubs manager Dusty Baker said of Mateo. "We wanted, hopefully, five out of him and then go to the bullpen. The lefties they have over there were hitting him pretty good. Things were working out as scripted. As usual, something goes wrong with the script."
It's been that kind of season for the Cubs.
Mateo did leave an impression on Clemens when he hit him with a pitch with one out in the fifth. The Astros starter retaliated in the sixth by hitting pinch-hitter Ryan Theriot, who was batting for Mateo. Home-plate umpire Jeff Kellogg issued a warning to both teams.
Cubs reliever Scott Eyre had to leave the game in the eighth with a strained right hamstring. His status was day-to-day.