"It was definitely one of those things, I wanted to end the season on a positive note and just give the team a chance to win, and today things just kind of went my way," Harrell said.
The Astros, who have won six of their last 10 games, ran their scoreless streak to 18 innings following Jordan Lyles' complete-game gem on Sunday in Milwaukee. Jose Valdez, Fernando Rodriguez and Wesley Wright combined to polish off the two-hitter.
The Cubs never had a batter reach base following Anthony Rizzo's leadoff double in the fourth inning, as Astros pitchers sent down the final 18 in a row.
"There was a little bit of sleepwalking at the plate today," Cubs manager Dale Sveum said.
Harrell allowed just two hits and struck out seven batters to win for the first time since Aug. 14, breaking a three-game losing streak. He finished the season at .500, which is an impressive achievement on a team that has won just 54 games.
"It was one of those things you know you've got to prove every day that you can pitch here, especially on a young team like this," he said. "I want to try to be one of the leaders by example on the field and by my play, and hopefully I displayed that."
The Astros have been keeping a close watch on Harrell's workload and had planned on him throwing only five innings, but he was on such a roll and was so efficient, they let him pitch a 1-2-3 sixth inning. He retired the final nine batters he faced and 16 of the final 17 to finish with 193 2/3 innings -- the third-highest total by an Astros rookie in team history.
"My arm feels good," he said. "I feel like I'm a little bit older so I feel like I can handle the innings, and it's just one of those things where I have to see if I can go out there and do it every year."
Fernando Martinez launched a homer out of Wrigley Field in the second inning, giving him homers in three consecutive games, and Matt Dominguez added an RBI triple in the fourth inning. Scott Moore had an RBI single in the eighth.
"Martinez continues to swing the bat and prove that hopefully he's the guy that can drive 25 homers," Astros interim manager Tony DeFrancesco said. "If he can do that, that's another spot we can use down the road here."
Dominguez, acquired from the Marlins in the Carlos Lee trade on July 4, has hit safely in 11 consecutive road games, the second longest active streak in the National League. He's 18-for-42 with three homers and 11 RBIs during that stretch.
"That was a big run, the [triple] down the left-field line," DeFrancesco said. "I always thought he could play defense when I've seen him, but now he's showing he can drive a baseball and be consistent. I think he's going to be a big part of this down the road. He has potential, and we're counting on him to hopefully be the guy."
Harrell was one of the Astros' biggest feel-good stories in a season needing a silver lining or two. Plucked off waivers last year from the White Sox, he came to spring camp as a long shot to win a job in the rotation and had been actually ruled out of the rotation at one point before pitching his way back into the mix.
He leads all NL rookies in innings pitched and ranks second among NL rookies in wins.
"Last year when he was with me [at Triple-A Oklahoma City], I saw the competitor in him," DeFrancesco said. "At times, the stuff wasn't as sharp as he is up here for some reason. Right now, this guy looks like he can compete, he can drive a ball on the inside part of the plate, he has a good slider, lefty-righty matchups he stayed strong. To get 11 wins for us is something very special just because of the way the season went."