Lester opened the month by tossing a one-run, complete-game gem against the Giants at Wrigley Field before turning in three scoreless outings, two of which came against the rival Cardinals. He also tossed seven innings of one-run ball against the Reds, ending his season Saturday against Cincinnati by giving up five runs in five innings at Great American Ball Park.
This is Lester's fourth career monthly honor and second of the season after being named NL Pitcher of the Month for June.
The 32-year-old ended his second regular season in Chicago with a 19-5 record and a 2.44 ERA in 32 starts.
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. This story was not subject to the approval of Major League Baseball or its clubs.