The right-hander admitted he was thinking about a possible no-hitter after the first three innings, but just a little bit.
"There's still so much work to do throughout the game to get to the point where it becomes a serious possibility," Arrieta said. "Knowing you haven't given up hits through three is kind of a momentum boost moving forward to the fourth and fifth innings, to kind of build confidence a little bit executing pitches. It creeps in there from time to time."
The Reds didn't hit Arrieta hard, just found holes.
"At the end of the day, they put some good swings on balls that were off the plate," Arrieta said. "Their guy [Anthony DeSclafani] was tough. He pitched a really good game, stayed out of the middle of the plate, and had some good life on his fastball. From start to finish, they were solid."
Arrieta has thrown six consecutive quality starts, and 12 in a row at Wrigley Field.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.